Why I can't win when I'm drunk?

In a nutshell, neurotoxicity.

Have you tried Mountain Dew?

You'd be hard-pressed to find a common psychoactive chemical that I HAVEN'T tried.

I think it's lack of impulse control. When I'm way-shted, I don't scrutinize my moves as carefully and I'm like whatever. I also tend to play more yolo-ish moves (aka poorly calculated sacrifices).

"The trick is to always play drunk. That way your rating is your drunk rating and you can have good games even then!"

my chess career

I agree with OhNoMyPants. There is such a thing called state dependent learning. If you are always drunk when you learn you will only do well when you are drunk.

When I've played drunk I see noticeable improvement; sometimes I feel I overthink moves, and with a spot of drink that goes straight away!

It is very true regarding the above tropic. Is it not? I do not drink any form of alcohol. Friends are you all serious or just joking? One cannot think clearly when one is drunk. LOL, bye friends