There seems to be a sort of "circle of life" when it comes to fighting. Most fighters watch the sport, take up the sport, fight for money and then end their career to just watch the sport again.
Many of these fighters come into the sport with a specialty or background such as karate or wrestling. They are so well-versed in these aspects that they can impart their knowledge on others.
Guys like Tito Ortiz and Pat Miletich have walked away from the sport, but have their own gyms to train fighters. Here are some fighters that need to open their own gyms when it's all said and done.