Why do men shut down when they get sick?

I have noticed this about men lately--whenever they get sick they act like it's the end of the world. My dad whines and complains when he has a cold and yet my mom never complains when she is suffering from bronchitis. There's a boy in my school who won't come into school when he has headaches, he complains he can't think and concentrate, and yet my best friend suffers from clustered migraines to the point she shakes, but she still goes to school. I know some other guys that get simple colds and curl up in corners and basically act like they are going to die. I'm not trying to knock one gender or another, but are guys just not used to being sick? I see guys freak out over headaches, but girls have severe migraines and act as if nothing is wrong. Is this just me or has anyone else noticed this?