Why am I always embarrassed by the things I did the year before?

When I was 13, i used to write my older sister cute notes and put it under her pillow. And she didnt seem to care. and i hate that i did that so much. cant even remember it without making a face

When I was 14, i cried because I wished I was born in the era my favourite group of actors were doing their most popular shows in.

When I was 15, I used to argue with people online about actresses and prove how my actress was better than theirs lol.

I was so mature through my studies, my responsibility at home and taking care of my nieces but I was childish in other ways.

Now I doubt if I am doing something I might be embarrassed by in the future.