It’s hard to walk away from the spotlight, the money, and the fame, which is why so many end up returning to act ion, usually to diminishing returns -- with UFC Hall of Famer and former two-weight class champion B.J. Penn frequently mentioned near the top of the list of those who overstayed their welcome.
Rutten himself stepped away from mixed martial arts in 1999 after downing Kevin Randleman at UFC 20 to win the UFC heavyweight title. Injuries forced his hand; he left the sport unbeaten in his previous 21 fights.