You're quite right, being overweight is not okay. It's unhealthy, expensive and unnatural.
And don't worry, you won't bore anyone here with weight-loss talk - we're all pretty much immune from that.
You imply that you've lost weight before but put it back on - that happens to a lot of people. I think someone here, Blitz, or perhaps Metalcharm, mentioned not long ago that weight-loss has two separate parts: (1) Losing the weight, and (2) Keeping it off forever. Food for thought, eh?
One way to help motivate yourself, as well as keeping yourself honest, is to join in the Challenges and diary your progress on the Personal Progress board. Just create a new topic with a unique name and reply to it with regular progress updates. Having it there for all to see - your progress as well as intentions and goals will help spur you on your way.
Anyway, don't forget to check out the articles on the main website (they're quite interesting and useful), and the Facebook page. See you around.