Some people are very resilient and can maintain their inner balance even around the most negative of people.
Some are basically emotional and philosophical sponges and absorb every nuance of anothers attitude without much effort.
I'm rather more like the second than the first. So I try to decompress after I'm around other people by going off by myself and re-centering.
I believe the answer to your question is going to vary from person to person, and their respective level of self awareness.