The Truth About Playing "Rushes"

We've all been there. We win a few hands in a row and, predictably, start telling jokes, high-fiving and gleefully stacking chips while broadcasting our genius to all within earshot.
It is almost irresistible. We're on a "rush." It's a real high. We feel invulnerable. We believe it was our skill that led to this tsunami of chips in front of us.
Eventually reality will tiptoe back in, but who cares? Of course, there isn't anything wrong with this. Winning a whole lot of chips is great fun and if we can't enjoy these moments, what's the point?
But, on many an occasion the guy marked cards who just went on that rush will then do something very interesting.
He'll look down at his cards on the next hand, call an early-position raise from a tight player and say, almost sheepishly, "Hey man, gotta play my rush" and proceed to make what he knows is a strategically poor play.
Is this sensible? Is it smart to play a rush - in the sense that, in the long run, doing so provides additional profits? Or is it stupid - in the equivalent sense that it costs you money in the long run? In short, are rushes "real?"
The answers are tricky. I can think of at least three fairly obvious reasons why someone might want to play a rush, not of all of them convincing.