These are people around you who are negative towards you or the things you do. This is done in a constant small way and gradually drain your energy and enthusiasm.
Yes i do or rather did. She has been my friend since school i've always just let the comments go straight over my head, but just recently she seems to be getting more bitter, and even started lying. So i've told her straight that i'm no longer willing to put up with it, if she wants to be my friend then she stops the crap. I've not heard from her since, it's all pretty sad really.