Annoying, isn't it!
I agree with
@helensaramay that perceptions have changed and slim people are now looked on as skinny, and the overweight are looked on as normal because it now is normal. Also your acquaintances may only see you from time to time so big changes in your weight are more noticeable. There is probably more than a little jealousy involved too. I had similar comments when I lost all my weight. No-one comments these days.
You are happy with your weight and how you look, so be proud and show your new figure off to its best advantage.