Probability
Intuitive
Explanations in this section should contain no formulas, but instead colloquial things like you would hear them during a coffee break or at a cocktail party.
Concrete
https://mathigon.org/course/probability
Probability Theory: A Concise Course by Y.A. Rozanov - a great book that starts completely at the beginning and goes a long way in only 148 pages.
Abstract
The motto in this section is:
the higher the level of abstraction, the better
.
Why is it interesting?
quantum mechanics
,
quantum field theory
,
Statistics
,
statistical mechanics