I absolutely don't believe in the genetic reasons because for me it tends to shift every few years. Let's take out childhood and puberty and only see my adult l

I absolutely don't believe in the genetic reasons because for me it tends to shift every few years. Let's take out childhood and puberty and only see my adult life. I can go years on 6h of sleep and everything's perfect (usually sleep 9h on the weekends) and then there's years where I absolutely need my 8h to function. Sometimes it's easy to get up at 6 sometimes I could sleep in to 9 every day. It has nothing to do with summer or winter, that much I can tell. I am not a morning person, but compared to other people it's fine. So yeah, maybe there is some reason I've never discovered why it shifts so much (eating habits, weight, general mood) - but I can only say it shifts every few months or years and hasn't significantly changed since I am an "adult".