Sure. But yesterdays mistakes can be punished today. ie all evolution happens in retrospect - a mutation haopens - the world tells you after the fact whether that was good or bad. Evolution is hindsight in action. In hindsight - taking antibiotics everyday might have been a bad idea.

> Eh, the main downside in the short run is that you are killing your gut fauna.

Sure - thus increasing your chances for being colonised by an unfriendly and antibiotic resistent bug - which may result in your death - which in hindsight was obviously a bad idea....