Why was past me such a loser

Kind of random but just kinda something I've had on the mind for a long time, it feels like I cringe to hell and back at my old self constantly, and I only really have a few years I look back on and was like "yeah i was alright then". Like the only years I really consider to be "good" (both in terms of personality and things that happened to me) were 2018, 2021, and last year. But just speaking from ages, I sorta have this weird trend where the "first half" of me being a certain age is completely different from the "second half", like for reference, my birthday is in June so it's sorta perfectly split, so from about June-December I act a certain way and have certain interests, but from January-June I sorta become a different person, interests are similar but personality is generally pretty different, unless if I decide to drastically alter myself (like I did when I was 17, was initially super into Guitar Hero and stuff for about a year but dropped all that because I associated the series with a serious downwards spiral I was going through, so went back to Tony Hawk and everything I liked when I was 15 since that was before the spiral started once December rolled around), so the "first half" of an age can be way better than the "second half" like when I was 18. But got a bit off-topic, my point is that I constantly cringe to death about how I was excluding a few years, I can excuse the years of me being a kid because like, I was a kid, you're bound to do embarrassing stuff (though it still keeps me up at night), though after I turned 13 I kinda stopped having an excuse, but idk, hindsight is 20/20 and whatnot.

Though I guess me cringing at my past self is just a sign I'm growing as a person so maybe that's a good thing? But it still makes me die inside.