>So how hard or how many math domains should one learn to be able to understand all major CS theory? Understand "all major CS theory"? ...you need all the math

>So how hard or how many math domains should one learn to be able to understand all major CS theory? Understand "all major CS theory"? ...you need all the math However, you'll never understand "all major CS theory" (maybe Donald Knuth does...but no one else does, that's for sure) - so focus on what you want to know/do, then study the math that's related to it (at least enough to be passingly conversant) Best way to figure out the math you need to know is to survey the math requirements of several CS degree programs ...people far smarter than you have been working on this far longer than you've been alive - and their work is show in the degree requirements :)