Damn
3, duh. (My ex's 9 year old little sister told me this joke, and followed is up with: "and YOU'RE the math guy!" >< Burned.)
In both cases you wish you took it out a few seconds earlier.
It was the best dam show I ever saw
None, because they keep on asking why all of the other light bulbs in the house aren't being changed at the same time.
There wasn't mushroom.