Just chiming in, I remember people telling me this when I was 21 and thinking "I know things, these people are just talking down to me."

Almost a decade later, I can absolutely confirm, I knew almost nothing about the world at 21.

This is great advice. You need to fail and learn lessons. Your early 20's are the opportune time to fuck up because you get a lot of free passes. Those free passes start to run out as you get older.

Use them, because they're non-transferable