Why take a chance? Your education may be all for nothing if you suffer a bad enough head injury. If you are worried, wear a helmet. 25 years ago I bought my girlfriend a helmet. When we split up she stopped wearing it. Soon after she hit a pothole and fell off her bike. While she didn't hit her head, but the bike fell on it and held her head to the pavement as she slid down a hill scraping the skin off the side of her head. Had she been wearing the helmet her injuries would have been small or even none. If you are worried about attracting a mate, a closed head injury will make it that much more difficult.