First day to the 5 km run....

OK so for my first day on the "lets get healthy and clean up my life" and i am running 5 kms in 10 weeks.... I failed my first run/walk. I only got to do 12mins, wen i basically decided i had, had enough and couldn't be bothered to keep going. I was walking in bare feet on the grass around our house, as my youngest was still inside asleep and my eldest was outside playing with the cat. This is not a good start at all. Now all i wanna do is sit on the sofa with my packet of chocolate biscuits and eat them :( - So i have chosen not to eat the pack of chocolate biscuits but to get off this sofa and have another go. So this time i have given up on the run today, and just try for a 30min work. So i made 20mins before my partner turned up home and then we decided that i should go for a walk with him across the farm. So instead of doing the extra ten mins walking around the house, i drove up the road and walked around two big hills for the next 40mins. Not a bad effort - expect still no running so we will try again tomorrow for that run. Still every proud of myself.
Alot of people think why? Why are you putting yourself through that and its alot harder than a walk that we do with the kids etc... WHY? why not? I am up for the task just so i can say i have done it, worked hard to get there but i have completed it.