Why is it when you grow fat people comment to you but when you lose weight no one says a thing?

After being obeese for years and hearing people joke about it, or my relatives saying my goodness have you gained weight again, I decided to lose my gut and get ripping fit. And I did. But I did not get any comment whatsover from people who for years used to flick insults at me and make snide comments. They pretend as if nothing at all has changed with me. Now why should that be?