One regret (but not really) - is not using the lessons from value investing earlier in life.
Imagine a life where very early you “invest” long term on your best 5 ideas in life - relationship, music, design, learning, health, etc. And you go all in. Every day you “invest” with your limited time and effort - to gain 7% improvement in those goals every year. Compound that return over a few decades and a person could reach wonderful heights in life.
Like investing - the biggest challenge is finding the punchcard things that you can invest in for life that will generate for you specifically the most happiness and/or reward. Also like investing you can just chose life “index funds”, the human basics like health, nutrition, relationships, learning, etc. and maybe later you can add synthesizers, piano, Ableton