I always miss them so much in languages that don't have them. It is just such a common situation to be in where you have something that can only be X, Y, or Z,

I always miss them so much in languages that don't have them. It is just such a common situation to be in where you have something that can only be X, Y, or Z, where X, Y, or Z are separate types. And then being able to pattern match over it to guarantee all cases are handled. Just perfect.