Love John Bingham and agree with him whole-heartedly!
The main thing is to decide if you want to be a life long runner, which is very different from a 'once in a lifetime' runner. A long term runner has to be able to see beyond the next run, the next race, the next goal, and be willing to put those aside when needed. Skipping an important long run, dropping out of a planned and trained for race, taking a week (or longer off) to let your body adjust and heal nagging nuisance injuries are vital to avoiding a big injury that will mean an end to running. And NO runner likes to pull out of a race, skip a week of running, etc. But once you are able to do THAT, then you know you are in it for a lifetime :), not a particular event.
Welcome, and happy running :)
"I just felt like running." Forrest Gump