Runners?

[Trabby]

I am not a runner or fitness buff by any means... Back in the day I ran for a couple months and really enjoyed it... My knees however did not... Now 15 yrs...20lbs heavier.. And many cigarettes smoked later... I'm wanting to start running... I would eventually like to run a half or full marathon.. ( it's on the bucket list so hopefully I have awhile) Obviously I should quit smoking.... I like smoking ....
So my question to our reefing runners...
How did you get started? What keeps you motivated?