Does it have to be a problem (a bad thing) or an incident (something that happened to us, as opposed to something we did ourselves)? Or just any unforgettble memory? ![:stuck_out_tongue: :stuck_out_tongue:](https://forums.tapas.io/images/emoji/emoji_one/stuck_out_tongue.png?v=3)
(I realized that I had to think about this, which means I've temporarily forgotten anything that might be a candidate for this, which means all my memories are technically forgettable XD)