[onecool]

A Russian mathematics professor of mine in graduate school was a student under Kolmogorov. He taught information theory and algebraic combinatorics and helped develop a number of systems for the Soviets. He was extremely challenging, but he cared less about the grades and more that you were understanding the material.

He would say at the beginning of the semester: "You must learn to build the castles in your mind." The visualization of the constructions really helps to understand how to apply the concepts in different contexts.

The Polish professor would hand out chocolate to every student before every test, so that your mind was more relaxed.