Because

This may be a fine program
but it's not going to work for me,
I know since I've tried everything,
most of them multiple times...
like Weight Watchers, Adkins diet,
those candies, do you remember,
Aids before that meant something else,
counting calories, carbs, protein,
grapefruits, and lots and lots of them,
exercise, yoga, walking five miles a day,
and hypnosis, ear staples, therapy,
public dares, incentives, charts...
even giving myself shots in the stomach
daily, not approved for weight loss,
just for diabetes which I don't have,
but they might have worked,
and didn't any more than the carb blockers,
the appetite suppressants, even amphetamines,
you name it I tried it, and it didn't work,

so this one won't either, even though you swear
it worked for you, even if you tell my story
like you sneaked a peek in my mind,
even if you seem different from any other group,
but it won't work for me, and I tell you this
to say I'll take your dare and try it just to prove to you
it won't work for me.