rhetorical question

Am learning a lot this month, both for and about myself (it's definitely been a period of trying and stretching). But half the time I find that I wind up berating myself for stuff that just came out of my mouth, stuff that I didn't think twice about saying or doing. Was wondering if I can catch myself doing stupid stuff earlier and earlier, til I can finally see it coming and prevent myself doing it :)

Why do lessons always have to be learnt in retrospect?