I was a teetotaler until my late 20s when I decided to try to develop a taste for wine for social reasons. Fast-forward 30 years and today my wife and I have a cocktail and a glass of wine most nights. That sounds like two drinks, but one day I started measuring how much alcohol I was actually putting in to the cocktails and they turned out to be triples. So technically we're having 4 drinks a day. We get a slight buzz, but never feel impaired, never drink before dinner time, and never have hangovers. When we travel we will often go a few days without drinking at all and it's no problem. A few years ago I bought a blood-alcohol meter and have never registered above the legal limit, even immediately when I feel buzzed. The highest I've ever registered is 0.04. And over the years I've used three difference BAC meters with consistent results.

I think the conclusion to draw here is not that having 4-5 drinks a day is no big deal, but that different people react to alcohol and other drugs differently. For some people, like me, it turns out to be no big deal. For others I'm pretty sure it would be a very big deal. A one-size-fits-all drug policy is never going to work.