Trying to understand this person

Content warning CSA?
Ok sorry about this weird as fuck question but literally i just wanna understand

So when i was rlly young, like 12/13 i was molested multiple times by my dad. Like a couple were when i was awake but i caught him with hands in my pants middle of the night once. So like tbh i dont even remember clearly for how long. (Lmao at that time i literally just shoved the incident in the deepest part of my brain only for it to come out with 300x the amount of mental damage 10yrs later)

It stopped at some point. I thought maybe he moved onto my other siblings. But thankfully it looks like they weren’t SAed (i was pretty anxious about it during that time and tried to never let them be alone. i once tried to hint at dad doing something inappropriate sexually and got shit on pretty harshly by all of em. Made me sad but also glad since that also meant they didn’t experience it and even me hinting that,was outrageous for them. Maybe idk what actually happened with my siblings and im just going off of circumstantial stuff)

So What compelled him to do that? Do some brain broken people just get horny and touch their children? Did he just move onto someone else (like my mom)? Im hoping nothing happened outside of my house. But like what is the mechanics you know what i mean. Like is he just a sleeper pedo that got activated all of a sudden then shut down (hopefully permanently)

Is it possible that theres actually no proper way of understanding this behaviour and sometimes people just do vile shit? And then have this like post nut clarity like “oh shit i fucked up”
I guess this would help me kinda come to terms with the fact that im hoping there are no other victims aside from like me and my mom (if he forced her to do stuff)
Lol thanks for anyone who responded
Sorry abt this weird asf question. Im gnna delete this once i get any answer agdbdka