I have forgotten about a concert after paying for the tickets, I have forgotten about super important plans and didn't even send a text to the person I had them with until about 6 hours later (in fairness I never even got a text or call from them in that time, just a "where were you, I waited" when I called to apologize) and I have forgotten my entire wallet at a restaurant. Sat it down while waiting for my card back and put the card in my pocket and left the wallet on the table.

I have also unironically said this.