I have very similar feelings towards my memories. I'd like to tell you why and offer a solution that's been very transformative for me -- and even for those closest to me.
Writing them down is one of the best things you can do here. Maybe for yourself in general, but that's a different rabbit hole.
I'm approaching 30 and it's only for the past couple of years that I've been journalling things consistently. I started after stumbling upon a very old notebook that I used for all sorts of stuff: writing short bits of fiction, making small notes, processing my feelings, doodling, etc. Between that moment and the oldest entry passed maybe 5-6 years at the time -- and I was shocked to find out how much of that I had forgotten to a point that I felt a jolt reading about them; like a memory injected into my brain, suddenly and all at once.
I can't say every single one of them was pleasant, but over the years, each and every one of them felt valuable. I can't imagine what it would feel like to be reading about your past self from 10, 20, 30 years ago -- that's gotta be like reading about someone else entirely, but much weirder, because you know you're the same person.
Write that down. Don't overthink it -- don't look for systems, don't optimize, don't make it pretty. Just write, and in time, you'll find the way that works for you the most.
And backup. You're one accident away from losing years or decades worth of your life's most dearest memories. If you write by hand, either take photos and back them up (multiple times, different mediums), or digitalize them and then do multiple backups as well. I am speaking from experience.
