I understand that you don't want to talk to random people on the street, but I disagree strongly with "just doing your job" mentality. If you have any sort of creative output job where you work within a team (engineering, academia, some artistic endeavors), things are different.

Companies often pay for their employees to attend professional and technical development workshops or go to conferences, because part of your job is to improve your skills. Casual water cooler talks do the same thing; they improve your skills, and help initiate creative ideas that ultimately help build better things.

In my own PhD, I saw supervisors demand their students attend department get together, bar hangouts at conferences, and even casually talk to other people in the dept. If I was a manager of creative types, I would absolutely rate someone who didn't "waste their time" at work lower, because if your job description is to create, you need to do reasonable things to improve your creative skills and outputs.