1. The person who "doesn't need anything."
2. The person who "already has everything."
3. The person who wants a very specific gift(s).
4. The co-worker you got as a Secret Santa.
You've talked to them twice. All you know about them is that they breathe, and every once in a while they mention that they eat. Buy them a goldfish, because then at least when you see them, you can say, "Hey, how's that goldfish? Still alive?"