Ever lose something expensive?

[RagnaToad]

So I ordered some expensive film for a view camera, about €170 euro worth of film.
It finally arrived. I had to go pick it up in a town that was nowhere near my hometown. A 45 minute drive.

Then when I took the train to the city I live in during the week, I ****ing left the package with the boxes of film in the railway station.
In the end I went back and my brother had gone to see if they had it still, and they did.

So I almost lost €170 worth of film. Felt like an idiot and was happy when I got it back.

What did you stupidly (almost) lose?