Power
While there are dozens of acceptable mixed martial arts techniques, the eight-sided cage format we all know and love is derived from an ancient Greco-Roman Olympic wrestling/boxing hybrid sport called Pankration, which literally means "all powerful" (source). Try to remember that when your opponent is using the side of the cage as a cheese grater.
This sport is all about power. From the freakishly massive and/or athletic human specimens themselves to the grappling and submission moves, the whole point of the sport is to defeat your opponent using your body against their body. That fifteen-minute bear hug is a test of (wo)man-vs.-(wo)man to literally answer the age-old question "Who would win in a fight?"
There's also a certain danger level to all this power you've cultivated. You have the power to accidentally break someone's neck. That is quite a lot of power, but not really the kind you want to exercise. No, you want to almost break their neck, but leave them just alive enough to tap on your shoulder and let you have this one.
And again, there's that "danger" thing. Many of the pro fighters are just really good at knocking people around and want to make a lot of money doing it. Those are the ones to watch out for—the fighters who delight in the pain and the battle. They usually know what they're doing, and the only way you'll be able to overpower them is to know what you're doing.
That means lots of training and practice.