Here's some science, showing what happens in practice:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4321715/
As we all know, one of the first effects of alcohol is to make you want more alcohol, but the euphoria soon wears off with increased consumption. Some of us learn to drink slowly and maintain the optimum level, a gentle buzz without disinhibition and danger; others, genetically different, never do, and don't realise they're in a trap until it snaps shut around them.