So he doesn't remember his childhood? Could this be a trauma response?

He does remember. But you can't remember EVERY single thing about your childhood, most people don't.

Well you can't remember the detail if your childhood especially when you get beaten for the most of it.

*of

I think yeah, he just blocked some of it.

I know plenty of people said it, but as someone’s whose childhood was traumatic, it’s extremely common to forget parts of your childhood due to cortisol being produced. This hormone is what usually triggers the “fight/flight/fawn/etc.” reactions. It’s your brain trying to help you survive situations, but it also makes you lose ability to retain memory. So if I think about my childhood I’ll remember more bad things than good, and I won’t remember being a certain way.
Ofc plenty of people could just not remember their childhood well, but in this context I find it relatable.