If I can run 26.2 miles... Why not 50?

It's 2014 and I've decided to train for a 50-miler. No specific reason.  No symbolic tie to this particular year.  I'm planning to run a 50-mile race because I think I can, so why not try.

I feel like I should say something profound about my running history or my motivation for tackling an ultra distance... but there's nothing really that extreme or compelling about it at all.  That said, here's a bit of background, for context:

I used to hate running. Once when I was a kid, I decided to join my Dad for a run around the block.  As the starting forward for my basketball team, I figured I'd be able to run circles around the man whose workout gear consisted of an all-grey sweat suit, white tube socks and all-white Reeboks. By the time we got to the end of the street—no more than 10 minutes later—I was winded, bored and completely bewildered as to why he chose to do this on a regular basis.  I pleaded for the man to go on without me, and when he flat-out refused, I huffed and puffed dramatically all the way back home, making sure to convey the deep sense of pain and anguish this senseless activity was causing me.

After high school was over—and with it my basketball career—I bit the bullet and started jogging to stay in shape.  Soon, that first feeble attempt to complete one measly loop around the block turned into several loops, and ultimately a super loopy course that squiggled through the heart of our neighborhood from top to bottom before ending back at home. I was pretty proud.  Slowly achieving more and more made me want to keep going.  I wasn't just running the rounds, I was twisting and turning through a grid of streets and houses... not because it made sense, but because I realized I had the ability to do more.  (In retrospect, it was probably only four miles total. But at the time I thought those squiggles represented some very serious mileage.)

The summer after my college graduation I started training for my first marathon.  Even though by then I considered myself a decent neighborhood jogger, 26.2 miles seemed like a near-impossible feat.  (I actually never would have thought to sign up had it not been for my best friend, Sheila, who decided that running dozens of miles might be a fun way to occupy our time post-college.) It became the only major goal I had in those few months after graduation when I was living at home and trying to figure out my next steps. It was the first time I attempted a long-distance run. And the first time I realized how far I could actually go with my own two feet.

Four marathons later, I've got my eye on 50.  Why?  I suppose it's just because...

Why not?