Is it normal for me to wet the bed when i am 20?

Urinary tract infection maybe

Don't drink liquids after 8 PM and see a doctor.

Don't piss in your dreams.

Completely normal if you're dreaming it. Try to wake yourself since you know what is happening.

Could be wet dreams you could still not be done with puberty

See a doctor.

I'm 21 and I went through a weird phase earlier this year where I wet the bed at least once every 2 - 3 weeks, sometimes multiple times in one week. I even had to get a new bed and everything! But just as suddenly as it started, it stopped. I'm terrified of it happening again, though, so I pee as often as I can before I go to bed. That seems to do the trick.

Usually ppl start young stop at like 4 or 5 and start again around there 80s

I used to live with a little guy who pissed the bed when he got drunk. He was in his mid twenties.

I would say it's not normal, but it's not particularly absurd or anything. I was still wetting the bed until I was in my early teens.
Just visit a doctor, and they'll refer you to a centre which specialises in such matters :) Once you've started treating it, it stops pretty quickly