The shock came with the laboratory work and introductory courses in chemistry and physics. I started to argue with the teaching assistants, I wanted to understand the discussed processes and experiments better and deeper, so I asked more and more questions. The answers I obtained didn't satisfy me, the arguments I was given didn't match, the introduced concepts were not clear enough, not precise, etc. On the whole all that created a feeling of confusion and disappointment in my mind.

... we arrived in Moscow in November 1951, greedy for science, mathematics, and philosophical discussions about politics, literature, art, theatre, music ... and we found all that in the Moscow academic and student community despite, sometimes, poor accommodation and life conditions and various shortcomings.

Menshov was a remarkable man and outstanding mathematician in real analysis and trigonometric series.

I was very glad, because it soon turned out that the decision was very good for me. With my background in real and complex analysis I quickly started to learn singular integral equations and related boundary value problems. I learned also about quasi-conformal mappings theory and the related Beltrami equation. It turned out that my studies under Ilya Vekua were very fruitful and continued for over two decades.

Andrey Kolmogorov, myself and four other young Polish mathematicians, my friends, we spent a week in the Tatra, high in the mountains, in Zakopane and around. The conditions were very hard: winter, frost, intensive snow falls, isolation. For a few days we were staying in a lonely hut high in a mountain valley, with nobody around, except us and an old woman, helping us with some food. Kolmogorov was sharing with us all the hardships of his life in these austere conditions. But there was always also some "scientific" component: in the evenings, after skiing or walking, or during meals or tea hours (not much, but also some wine) we also talked about mathematics. He was telling us about the theorems and concepts which he conceived or understood in his thoughts in the time between. And he was very proud of it, with the joy of a young man! Our impressions and what we all learned from Kolmogorov during those Tatra days are unforgettable for all our life.

In the middle of the winter of 1985-86, I read ... Bojarski's original works from the years 1955-57. With crystal clarity I understood then that Bojarski did beautiful and completely innovative things in mathematics, things that fully justify Hardy's phrase about what will be remembered someday. Bojarski's proof of the theorem on the existence and uniqueness of homeomorphic solutions of the Beltrami equation is short and clear, uses the latest achievements of mathematics at that time, has in the background geometry, complex and harmonic analysis, topology, and even a pinch of algebra, and above all ... that familiar feeling of how beautiful and simple it is. [I was] full of respect and admiration ...

From the end of the 1950s, Georgia (then a Soviet republic) attracted Bogdan Bojarski not only for the great achievements of Georgian mathematicians. Up to early 1960s, Bojarski visited his supervisor Vekua in Tbilisi and presented an impressive talk on the stability of partial indices of the boundary value problem at the famous Nikoloz Muskhelishvili seminar. He kept friendly contacts with Georgian mathematicians ... His favourite toast in a circle of friends was the dialog between two of them: "Do you know Lenin?" The answer was "No". "Do you know Stalin?" - "No. But I do know Givi, Saba and have many other good friends". Next, Bogdan would suggest drinking to the friends who we really know and who support each other.

I remember the first time I met him. On the first Wednesday of October 1984, at about 8:30 in the morning, Bogdan Bojarski entered one of the corner rooms on the seventh floor of the Palace of Culture, where a dozen or so male and female students of the then third year of the theoretical mathematics section at the University of Warsaw were waiting. He had a nondescript, grey-beige jacket, a worn and capacious leather briefcase, and glasses. He took a stack of papers out of the briefcase, definitely thicker than the notes needed for an hour and a half lecture, silently, thoughtfully, clearing his throat slightly, spread them out on the desk. And then he started talking.

His lecture was completely different from what we had experienced during the first two years of studies. Firstly, because in partial differential equations, the possibility of enjoying the beauty of a proof or a specific result usually requires breaking through a thicker layer of calculations than in many other parts of mathematics. Secondly, probably more importantly, because of Bojarski himself. His lectures were dominated by deep, anecdotal chaos. The inscriptions and calculations were rarely accompanied by clearly emphasised words such as definition, lemma, theorem, proof, organising the students' notes and attempts at thinking. He rarely erased the blackboard - when he ran out of space, he erased small windows in the thicket of inscriptions, wrote with different colours of chalk, sometimes between the lines. I don't think any of my lecturers at the University has ever heard so many silent, terrified sighs from the audience, such rolling of dejected eyes.

Bojarski, in a very paternalistic and suggestive way, was essentially telling us one thing throughout the entire semester - look, this is interesting, beautiful and important, and at the same time it can be so simple ... if only you put some effort into understanding it in your own way.

I consider myself lucky and proud to be Professor Bogdan Bojarski's former student. He never tutored me to become a routine mathematician, but prepared me to become an independent scholar. More importantly, he always believed in me and made me feel successful. I thank him for this. ... Bojarski's goal was not only to do research but also to serve the Department of Mathematics and the greater mathematical community. He became visible rather early as a gifted leader of the mathematical life at the University of Warsaw and Polish Academy of Sciences. Leadership was required from him and yet, in my personal experience, his passion and commitment to working with young scholars did not end. Passing knowledge and helping the young to achieve their own career is a thing that I have learnt from Professor Bojarski; nowadays it turns out well in my own interaction with young scholars from the United States, Italy, Finland and other countries. I think that unselfish devotion to the next generation is the noble duty and the highest responsibility every scientist should accept.

Bogdan Bojarski is the author of works that have become a permanent part of the world of mathematics. ... In the Polish mathematical community, the position and role of Prof Bojarski is exceptional. The formal expression of this is his function as Director of the Institute of Mathematics of the University of Warsaw, Secretary, and currently Chairman of the Committee of Mathematics of the Polish Academy of Sciences, and many others. However, the actual reason for this opinion is that Professor Bojarski's interests in mathematics go beyond the scope of his personal research, that he is deeply involved in the general issues of Polish mathematics, that he is an exceptionally sensitive scientist, teacher, and educator.

Under the leadership of Prof Czesław Olech, the Banach Centre gained international recognition as a centre for mathematical cooperation, hosting mathematicians from all over the world. Prof Bogdan Bojarski took over as director in 1993 after the termination of the original agreement between the Academies of Sciences. A new era of cooperation began, especially with the European Mathematical Society. New forms of activity were introduced, such as condensed workshops, symposia and interdisciplinary meetings, as well as thematic semesters.

When I look at Bojarski's achievements and the fates of his students, I find numerous confirmations of Czesław Olech's above assessment. Bojarski's achievements include not only works devoted to the Beltrami equation and the theory of quasiconformal transformations (on the plane and in higher dimensions), but also later works on the theory of Sobolev spaces, and finally works on global analysis, devoted to the neighbourhoods of the index theorem. Bojarski was a witness and participant in the emergence of one of the most important and profound areas of contemporary mathematics, where analysis and differential equations are applied in a global situation and find connections with geometry, topological, and algebraic properties of manifolds.

In general, he suggested rewriting the theory of generalised analytic functions in an invariant form. Bogdan Bojarski thought that this approach could be interesting not only in pure mathematics but could help us to understand the problems of modern theoretical physics. He named this conception 'Complex Geometry of the Real World'. When Bojarski was young his mind was occupied with the topological invariance of index. This led him to the famous Atiyah-Singer index theorem. Bojarski's thoughts on this question were published in the paper 'On the index problem for systems of singular integral equations' (1965). The scalar Riemann-Hilbert problem for a multiply connected domain was solved 40 years after his seminal results in 'On generalised Hilbert boundary value' (Russian) (1960) and his Supplement to Vekua's 'Generalised Analytic Functions' (1962). These results of Bojarski were the basis of the complete solution given in 2018. Although Bojarski did not address engineering problems directly, the boundary value problems considered by him have applications in continuum mechanics.