Sadly, I know this now, but you couldn't have told me this a year ago.

And I'd have argued with you too. What a different response I'd have posted a year ago.
A year ago I'd have said: But I do exercise, and I do so like a mad woman. I hit the gym 6 days a week, sometimes three hours at a time. And I follow South Beach without even one cheat. I am ridiculously honest with myself and still the weight does not come off. I am broken.
Today I can say: It's about persistence as much as it is about being on plan. Being really strict is great, but it must be sustainable. If you're going to go all out, that's fine, but you have to keep up with it and give it time because stalls happen to everyone. It wasn't that the weight wasn't coming off, it was that the weight wasn't coming off
fast enough for me, especially when I compared myself to others.
So yep...
given time, diet and exercise works and I now believe it can work for anyone with an exception rate of only maybe 1%.