Mid-80s, Moscow Railway. A railway worker trying to remember what he was taught at the institute, and then understand why it is needed in practical activities and whether it is necessary at all. I warn you in advance - questions will remain unanswered. The author remembers what an integral looks like and even leafed through Bradis’s tables in his distant childhood; there were no pictures there. Nobody will let him bend and overcome, and he himself understands that he won’t be able to master it. From the author: I wrote and worried: Will I be able to write a book or will I give up? in impotent anger like some other things? Smog. While I was writing, I was a little taken aback by the hero and giggled at his powerlessness in the face of real life without a laser sword and a laptop. I invite you to giggle with me. Not a single piano, not a single one at all!