Tell me if I'm crazy

For the past week, I've been considering something that might be a little insane.  I keep wavering between thinking that I can do this, and feeling overwhelmed at the prospect.  Here it is: I'm thinking of running a marathon.

It's an idea that's been ruminating in my mind for a while now, as a vague, 'someday' idea: running a marathon.  But since the company I worked for announced that they are sponsoring the Austin Marathon, I've been thinking that perhaps someday is 250 days from now.  26.2 miles to be covered while I'm still 26 (the day before my birthday).  The numbers are really aligning there, aren't they?  Okay, that's probably a sign of insanity, seeing meaning in numbers, but I can't help it.

The idea has been in my head for the past week, carefully revealed to just a few people so far.  I didn't want to mention it only to renege after coming to my senses.  There's nothing to make you feel less accomplished than for someone to say, 'Hey, weren't you going to run that marathon?' and have to admit that you never actually did.  But after several Google sessions about training, and coming to terms with the number of hours I will have to log, I think I'm tentatively ready to say that it's something I might do.  Possibly.  That's a commitment, of sorts.

I have a 5k to run this Thursday, which I'm thinking will be the kickstart of my pre-training running routine. So what I'm wanting from those of you out there in the world wide web is a sanity check: just how crazy am I?  And if you have any advice, please give it!