People usually give negative connotations to “hindsight”.
I don’t actually view it that way any more. To me, at least, hindsight is really a learning opportunity. If you make a decision in a particular situation and it doesn’t turn out the way you were hoping, next time you find yourself in the same or a similar situation, hopefully you are going to try something else. And with the benefit of hindsight you are probably going to have already considered what might have worked better, giving you the advantage of not having to decide on the fly what you are going to do.
The great thing about being “mature” (I use that term a little loosely, merely referring to the fact that I have a bit of life experience behind me) is that there are many situations one finds oneself in that one recognises from a previous experience. The other great thing is that the situation in question really doesn’t have to be the same on the outside even; one’s brain is able to translate effectively from even very loosely linked situations or experiences. This can be an advantage in learning new skills at an age where, typically, the “old” neurones are somewhat less flexible than in the brains of younger students.
Making mistakes is fine. That’s how we learn. Making the same mistakes again and again, knowingly, is an issue. Make a mistake. Work out (without beating yourself up over it) what you could have done better / differently. Move on. Next time you are in the same situation, go straight to your plan B.