Why, oh why?

Why does it take 15 minutes to consume a Hot Fudge Brownie Delight dessert, but it takes 5 1/2 hours to walk it off?

Why is it that when counting calories consumed in a day mentally it's so many fewer than when writen down?

Why is it that it takes 2 months to lose a measly 8 pounds and it only takes a week to put half of it back on again!?!? . . . hmmm, might have something to do with the Hot Fudge Brownie Delights . . .