When you are up so late or get so little sleep that you have the same symptoms as if you had been out at a bar/party pounding down the drinks... headache, stomachache, hungry, everything is loud, etc.
Man, I was at that party last night and didn't have a drink ... but was out so late I'm sleep hungover!
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.