Friend of mines Dad has been able to drink quite heavily for decades and nothing bad has really happened and he owns 3 houses, a business, Mercedes in the drive etc.
The key difference I see is that he can drink till he's drunk but when he says he has had enough, he has and goes to bed.
With me, it was so drunk I can't walk properly, but still thirsty, still wanting more.
No off switch whatsoever.