men aren't born equal. we are all different. many disorders are genetic, this starts some out at a disadvantage. also, things as arbitrary as one's birthdate can determine his chance of becoming an athlete (those born in january are much more likely to succeed in sports, and even go to college because they are a bit older than their peers and chosen at a young age for better training)
and one's attractiveness is also grounds for opportunity. this world is just not fair. but on the bright side, existence is beautiful and no matter what you are born with, it is also proven that a positive attitude will allow you to reach your potential. :)