Together with his paintings, attached to the walls there were quotes taken from some interviews and one really made me think:
I think an awful lot of creation is made out of, also, the self-criticism of an artist, and very often I think probably what makes one artist seem better than another his that his critical sense is more acute. It may not be that he is more gifted in any way but just that he has a better critical sense.
He was a painter so obviously he was talking about artists, but you can replace the word "artist" with "developer", "architect" or "writer" and the sentence will still be true: it applies to almost all jobs that involve some kind of creative process, like development, designing architecture of applications, writing tech articles and blog posts.
Don't just implement the first design you come out with, but try and refine looking at it from different angles before to start writing code.
Don't just release the first piece of code you come out with, but do a self review and try to make it clearer and better.
The best developers/architects are the ones that always criticized their own work in order to make it better.