Seemingly useless - surely counterintuitive
For me, mathematics is a passion, a game, a mystery and often a tool. Escaping into the world of math is liberating. Applying it to the real world is where I see my responsibility. It taught me to start with the easy things. Or at least the seemingly easy ones.
"Since people have started to prove the simplest claims, most of them turned out to be wrong."
Bertrand Russell
Since getting used to the notion of proof in maths, I have been hesitant to apply it in everyday life (particularly in the context of politics). The real world, being massively more complex than maths, doesn't allow for binary true/false categorization. Often, even falsification is difficult enough.
When solving problem sets, I find it useful to have insights in other people's work. During my math studies, a collection of math-related materials has formed. I share some of them here for self-study.
Analysis
Probability
Computer Science
Statistics
Numerics
Computational Numerics