So how should I approach more difficult math? On a lower math level it is possible to really understand a certain property, relation, formula, ... you can see where it's coming from: intuitive and/or by quickly derivating it in your head. But as the math becomes more difficult, this approach becomes of course impossible, the proofs become too hard to 'quickly derivate them in your head', so do I just have to accept certain properties, trusting on a proof I made in the past, without 'really' understanding what I'm doing? And what about certain intuitive concepts rigorously defined, like limits. Sometimes the 'symbols and calculations' make sense in a certain proof, but I don't really have the feeling I really understand what I just did, it doesn't seem reducible to fundamental logic/axioma's, there's no intuitive way to understand it. I hope this post makes a bit sense.