It's Testosterone and it's going through their testicles. It's a well known fact that high levels of testosterone cause a special valve in the corotid artery to close subsequently reducing blood flow to the brain. Parents should encourage their teenage boys to masturbate on a regular basis and in particular, before they drive. ( Here comes the science ....) Free blood Testosterone levels drop to basline immediately following orgasm and then take a few hours to reach a peak again. Having a baseline testosterone level reduces aggression, hence improving driving. Oh, and by the way, it stops you going bald. That's how you can tell the w*nk*rs in the pub....they're the ones with a full head of hair. Back on topic....have you tried www.swiftcover.com? They more than halved my insurance premium. Off for another haircut. Good Luck. Col.