What's the dumbest way you have lost money for no good reason?

It wasn't technically my money, but it was a lot. I was young, pretty and stupid (and pretty stupid) and worked at a hotel in Prague. It was a little hotel with only 20 rooms and they only served breakfast. After the maids left at around lunchtime, once all the rooms were clean and ready for the check-ins, I was on my own. At this time it was usually really quiet, the check-ins didn't usually start turning up until late afternoon, and all the guests already staying at the hotel were normally out for the day. So I made it a habit to walk across a plaza and down a short street to the local Starbucks to get myself a coffee and a little treat every day, then I walked back and watched some TV in the breakfast room or read a book. It was a pretty easy job. As it was a hotel reception, there was a lot of money. You'd think there'd be a safe of some kind, but you'd be wrong. It was late 2000s and Prague was a pretty safe place and it generally still is, so there was no real need for a safe, assuming that there was always someone available at the reception. Which... I wasn't. For those 15 or so minutes daily when I did my regular walk to Starbucks and back. Well, it didn't take long for some regular observer to notice my habit, and as soon as I left one day, he walked in, broke into the little rickety drawer where the money was kept (it wasn't hard to guess where the money was). There was a camera and the guys face was clearly visible, yet the police never found him .(Czech police are famously useless). There was some kind of an insurance policy in place, but the insurance company never paid up, as I literally abandoned the money and the insurance didn't cover that. It was one of the events of 2008 that completely changed my life, combined with other factors, and I'm actually proud to say I've become a more responsible and perhaps a little wiser person as a result. The hotel sued me for the money and although it was my fault, I had a pretty good lawyer and I was acquitted. Despite that, the two years it took to reach the verdict was a complete nightmare and my life was pretty miserable for a while. I guess I deserved that. Although I paid emotionally, I never paid a penny in damages. It was around £6000.