The human brain is an elaborate pattern-finding machine. It enthusiastically looks for patterns in the world which help improve your life.
If it ever feels like you need to learn the same lesson over and over without really getting it, that’s why. The lesson is there, but there has to be enough repetition for your brain to identify it as a pattern. That’s not likely to happen until the same lesson has happened a number of times. Until it’s a pattern, your brain just isn’t that interested, so you learn nothing.
The reason we associate wisdom with advanced age is that wisdom is identifying the patterns which are harder to see and need more repetition to deeply understand. That takes time.