I tend to do something stupid when I'm opening a new light for the first time.
Sometime back I got a Gerber IU. Slitting open the clamshell packing I took a hefty nick out of the lousy type II anodize in a rather obvious place (in fairness, the light is so worn now you cannot see this any more).
Putting the batteries in my brand new SL Propolly 4AA, sitting on the kitchen floor. . . put the batteries in, put the LED inside the head, screw it down, holding the light vertical. I hadn't thought that the switch could be in the 'on' position, and got a blast of light in the eyes when the head was screwed down enough to make contact.
Then only a month or so ago, when opening my new SF E2L from the clamshell package. Being aware of the Gerber IU damage, I sliced around the edge of the casing, expecting it would fall open. It didn't. I gave it a good pull and it came apart with a loud bang, sending the light flying through the air and landing heavily on the kitchen floor. Luckily, not a scratch. Ah, that's why you get quality lights!
Not exactly public humiliation, but I'm always entertained by my own stupidity anyway.