The former boxing champion almost didn't make it to the set of the 2009 comedy film, because he was too intoxicated to remember his appearance in the movie, until he met Zach Galifianakis and other co-stars at a club in Las Vegas randomly the night before the shoot.
"I met the guys in a club, they were in the VIP section and I said, 'This is where I normally sit, nobody's normally here,' " he recalled during a recent interview with self-help guru Tony Robbins. "So I went in there, I'm checking these guys to see what they're doing in my section. It was Zach, the other guy, and he said, 'We're going to be in a movie with you' and I said, 'Yeah? When?' And he said, 'Tomorrow.' "
"And I didn't know as I was drinking and smoking back then, doing drugs so I didn't know I was involved in the movie. So eventually I had to go and do the movie and it was a success."
Mike also made an appearance in the 2011 follow-up "The Hangover Part II". He has been sober for a decade.