I was decluttering in my office at work the other week, and I found a check for an embarrassingly large amount that I had failed to deposit in ... 2009. !!!!!

Luckily there was sort of a halfway good reason I hadn't deposited it then, we got it sorted out, and the issuer sent us a new one which is now safely in the bank account. It's nice when that kind of thing turns out all right despite the embarrassment!