Well, as for an embarrassing moment since I'm one of the lucky mods, I don't have much but last year for the ipsc training and first match - my uber reliable 1911 turned into the fable 1911 jamaholic once it was under oiled and out in some heavy rain.
I got some satisfaction from other pistols ending up the same, but my ego was still struck.
The next day was the first ipsc match, and on the first stage I was using some borrowed 8rd magazines. Into the prone position on a bench I go, squeeze the trigger, and click.
Half a dozen tap - rack but no bangs later, and I finally ditch the bad magazine and complete the stage with my time and ego in shatters.