I've recently discovered that my memory is selective not sure if that's the correct word...

Eg.1) I don't remember being a 'scary' child. Always thought I was sweet and timid, atleast that's what my memory displays.

Turns out I was a tiny (always the shortest,even n0w) despot! stranger still I played with boys, and they say they took orders from me,or else. or else what?? Was I demented? I know I have a history of blacking out when enraged, that's not the issue, people think I'm scary, was scary all my life... But nobody can say for sure why. And YTF do I not see myself that way as a child? I can understand why at present someone who knows me might call me scary, I'm easily angered and display it, also have a history of violent behaviour (but that was self-defense) still, i won't hold judgement over my friends and family calling me scary. They stick around and for the most part are really good to me.

Sorry, didn't mean to ramble.

Eg.2) went on an amazing holiday with my eldest and youngest brother once. We went exploring,it was a real adventure. My eldest brother moved overseas soon after and I only got the holiday pics a year later. When I recieved the pics i discovered something new.

My then SIL was in the photos!!

I can't remember her being there
there are vague 'glimpses' of her,but nothing concrete in my mind, like for all I know that could be a different holiday. Thing is, if there was bad blood between us then (which there wasn't bcoz my brother would've left her at home) or if she had started divorce proceedings, it would be understandable, that I blocked her out of that holiday, but we were close at the time

There are much more examples of my selective memory, and while I don't expect anybody to answer the 'why' (altho that certainly would be FANTASTIC), can someone atleast tell me they 'do' it too?