What this anon said:
>>12103018But to expand slightly, also remember that there's nothing wrong with hobbies or doing things for fun/curiosity. If you just need to get better at proofs, pretty much any undergraduate math text will help you more than this. But if you want some mathematical history don't let anyone stop you from checking out Principia. It uses geometric proofs for things we typically think of analytically though, so it will take a lot of getting used to and probably some secondary sources
