If you always follow some advice, you'll never experience why (or whether) it's good advice
An odd thought: If you always follow some piece of advice, you'll never know why it's good. You'll never know for sure that it is, either. That is: If you want to know why, you have to experience the bullshit that comes from not following it.
This almost sounds like a tautology. I don't think I've ever seen anyone articulate this in quite this way. The idea feels related to "you should try bad things," but distinct. If you don't try bad things, besides not experiencing the things you think are bad but are actually good, you also won't experience why the actually bad things are bad or the extent to which they are.
As a corollary, it is maybe worth sometimes not following what seems to be good advice to find out why and to what extent/in what sense it might be good.