What’s been your most brutal mistake?

By mistake I mean something that could’ve been avoided by being more careful. Getting PKed happens. DC’ing happens. I’m talking about REAL mistakes, like an accidental alch or teleporting out of an instance with loot on the ground.

I just accidentally opened an elite casket with a chance to fight the mimic. Was all geared up for my first ever mimic fight and accidentally opened it. Big yikes. I’m curious if anyone else has any gut-wrenching stories