Attaching a picture of my Gibson SG, which now features a detachable headstock. I forgot it was plugged in, ran over the cable with my office chair, and it met the floor.
I bought it for £1300 some time ago. Fortunately I think I'll be able to fix it, but atill very annoyed at myself.
Aside from scratching my car yhe day after passing my test, it's the lost expensive thing I've broken I believe (plus the car still worked – this… not so much).
Whats the most expensive silly mistake you've made?