The announcer on the Viagra commercial says, "Contact your doctor if your erection lasts more than 4 hours."

Wouldn't a man want to do that anyway ... whether he was taking Viagra or not?? I mean, is this something you've really gotta tell a guy? Why does he say that?

Or is this ... well ... "common" and normally wouldn't be a problem if a man wasn't taking Viagra?

Just curious.