lol
My most recent: Rebuilding my diffs backwards and not realizing it until I put it on the ground. Even thought the engine might have started backwards for a second but watching it speed off in reverse I almost but not quite, more or less kind of immediately realized my mistake.
Local park, wintertime, brand new Tmaxx with a stock radio. The guy was playing on the track, such as it is, and someone else on the same "color", turned their radio on. The TMaxx sped off to the east towards the lake, which was frozen. You might think that being frozen is a good thing, might keep the truck on top of the lake. The TMaxx sped out toward the middle of the lake and found a soft spot in the ice.
I ran into a tetherball pole at wot with my Kyosho USA1 Nitro Crusher. The chassis brace popped of and it looked like a taco. Thought "what the hell?", put it over my knee and bent it back. Popped the chassis braces back on and the O.S. RFB fired right back up.