One too many references to "the ug" on Sherdog. Curiosity got the better of me and obviously immediately after signing up I realized this was the forum for me. 
I lurked on a lot of sites but liked this one the best. Trolls weren't as bad then. I made my acct after 2-3 years of just lurking bc of the whole "join date" thing.
To crush my enemies...see them driven before me...to hear the lamentations of the women.
To troll KKMs.
Was looking for a place to bitch about the Bisping-Hamill decision, saw Cecil Peoples himself on here defending his scoring of the fight, never left
Because I kept getting banned. 
because I'm an Egg Goof Fuck with six months sprawl and sidestep traning with my black belt in Baboo Baby from Renee Gracie.
this bounty hunter is in traning so if you're coming on COME ON!!
LET ME BANG BRO!
i'd beat you with my devastating power but the guilt of hitting you is stopping me going above 70%
yomamafool - I heard Randy Couture and Royce Gracie posted here :-\
haha.. that was so long ago it seems.
I had to check last log in
Couture was 07 and Gracie was 08
Came for the AMA's, stayed to yell at SuperCalo for some reason.
Because I love forums with outdated, shitty software that don't tell you when someone's responded to you in a thread, use fucking raw HTML to edit stuff and have mobile modes and apps that suck ass.
In fact, I like it so much, I bought a blue name.
I'm now going to punch myself in the face, that's fun too.
for me was the 2nd PPV in a row back in late 2002 when joe said something to the effect of "people say a lot of stupid shit on the UG"
heh... was he wrong?
Google search for "Bang your cousin?" led me to the OG.
Actually was looking for an iPhone app a few years back and found it. Downloaded this thing, and well, the rest they say is history.
Has become one of the first things I do after waking up:
Get outta bed, stumble to my bathroom to drop some Major heat sticks, and hop on. Have a good time for the first 30-45 mins of my day reading all the wonderful shit you savages have to say. Then check back in throughout the day when I can.
Think I searched MMA on the App Store, possibly saw it mentioned in a magazine. Lurked for a couple of years before setting up an account. It's amazing how much time I actually spend on here.
Watched my first mma fight and rushed here to join up.
All other answers are just lies.
Came for the news and discussions Stayed for the trolling