I felt it was part of my real life. But after leaving the first company (then each subsequent company) I almost never saw any of them again.

People put on a polite friendly face at work, but that doesn’t mean they’re your intimate friends. Sometimes, but I think it’s not so common as you’re implying.

For me, the definition of what is "real" is: will I continue to be engaged if I didn't have to, e.g., if I was free of my need to work. My boss doesn't fall in that category, my friends (childhood / some good friends I made in my career) do. Is it possible to have a great boss who you can also consider a friend/mentor well after you are not working for them? Definitely, but that doesn't happen that often. So in absence of having that kind of relationship, yes, they are ancillary to my real life. How much time I spend with them in the work setting has nothing to do with it.

Of course it is part of my real life. Doesn’t mean that I necessarily like it, though. And I would be doing something else if I could. (Don’t tell my boss^W^W my noble leader though.)