Our surroundings is the core of all influences on our thinking and communicating.
Surrounding is something which influences mental state, physical state, perception etc and then bring about change in our behavior. We adapt to situations, people's reactions, customs, culture, geography and what not. And when we adapt we bring a change in our behavior too.
During childhood we used to do things as our parents used to tell us. When we grew up and started school we began to communicate with bigger circle of people. This changed our behavior. We started liking chocolate, candy, ice-creams not by choice but by influences ( surroundings). After that we went to colleges and universities we started interacting with new personalities and adapted to certain things.
Similarly you can relate to other phases of life.
The reason we see different behaviors around us is the level of exposure someone had in past (or present) with a particular surrounding and the extent of things perceived from different surroundings.