If there's one thing fans of MMA can count on, it's the fact that things happen fast.
One day you're witnessing the birth of "The Machida Era," and the next day you're seeing it end before it really began.
With so many fighters out there, sometimes it's easy to forget a name or a face, even if it's just for a little while.
Then, when you go back through your fight library and pop in a classic, a face comes on the screen and then you remember why you liked them.
And if they've seemingly disappeared from the sport, you wonder where they are now, and what they're doing.
Here are five fighters you may or may not know who seemed to go MIA from MMA.