I realize that when hit with a ball several times, you may not be thinking as straight as you used to, but the phrase, “Watch your head”, has always bothered me. Does anyone have the great wisdom to unlock the mystery of this rather moronic phrase? Granted there may have been an unsuccessful attempt at using mirrors in baseball to blind the opposing team, but my deep gut is not satisfied with this solution.
One synonym for “watch” is “mind.”
“Mind your surroundings” <-> “Watch your surroundings”
“Mind your grades” <-> “Watch your grades”
“Mind your head” <-> “Watch your head”
I don’t think it’s really any more or less complicated than that. Sure, it falls apart under scrutiny unless mirrors or cameras are involved, but a lot of idioms do.
Watch your mouth, Jragon!
Pay attention to where your head is, lest it abruptly come into contact with some hard object which would damage it.
Why, what did you think it meant? It makes perfect sense this way.
If you’re referring to sports - any sport - often the phrase is, “keep your head up.” Generally meaning pay attention and be acutely aware of what is going on in the game. Such as incoming fastballs.