The gig is over. You've sung your one or two (or three!) shows on closing night, taken your curtain call, done your meet-and-greet, and you are ready to eat dinner with your fellow artists and talk about how it all went. Or you might even be ready to go home, or to your hotel room, and go to sleep.
But the rest of the world has other plans. Someone important is throwing a party for you, and they entreat you to come "for just a little while", and your agent insists you go "just to put in an appearance", and your manager urges you to "swing by" and promises you won't have to stay long. Off you go, tired and hungry, hoping there will be food, hoping there won't be too much of a crowd, hoping you can be in bed before 2 AM.
Can you guess what happens when you walk through the door?
If you are a performer, you don't have to guess, because you already know. If you aren't, here are Noel Coward and Judy Garland explaining it all much better than I can.