Well, in a way, I lost it a long time ago.
I hate doing my taxes. Those forms are absolutely baffling to me. In the year 2000, the first year I made more than a neglegible amount of money, I worked for six months before starting school. In that time, my employer took $4,500 in taxes (26%). When tax time came, I picked up the tax forms, and spent some hours studying the so-called "guide" book, which is actually, I have decided, the government's way of suffocating people under a mountain of mysterious financial terminology. Eventually I gave up trying to figure out what it all meant, knowing that if the government owes you money, you don't get penalized for being late.
Well, I put it off, and put it off, and put it off again, until ... well, until now. Now I have found out that the government won't process returns more than three years old. I estimate I would have got about $3,000 back.
This is even worse than the time when I accidently left $440 in an envelope on a desk in one of my classes. But that's another story.