I'm not very good at keeping my personal life, personal, and my professional life, professional. It seems only natural to make myself perfectly comfortable where I have to spend 40+ hours a week, and vice versa. HELLO, if I like these people, I'm going to want to drink beers with them on my off time, not just fill out TPS reports.
I've done this EVERY job I've ever had. Work friends often cross the line into friend friends and they often have been some of my greatest delights. Before I know it, I'm gossiping at the water cooler about embarrassing things that shouldn't be spoken out loud while wearing security badges, and then the next day, I'm dragging myself into work hung over and that is always much more fun if there is someone else to blame.
Work friends are important especially here in DC. I've had more friends move in and move out and move back in (and then back out) than you could shake a stick at. People come here (and often go) from all walks of my life-- high school friends, college friends, hell; friends I met while living in different countries! But work friends often form bonds firm and fast because you know they are here to "stay". Not that jobs REALLY hold people down in this city, but you look at a work friend and you think maybe, "cubicles aren't conducive to rapid change. Please tell me that you'll stay for a bit and we can have some fun and laugh and drink beers and make faces at annoying people at work both on weekdays AND weekends!". And I don't mean that in a needy way, but when your friends are of the livelihood that they could do whatever they do in any city, it makes things more transient. Really, if you work in non-profit land, you work here. And here you will probably stay.
I don't know if this experience is universal or not. I highly doubt it. I am just sort of a social circle busy-body and mold them constantly. And I wouldn't say I have a specific circle of friends, even, because who does after college? But I really value them, however they are scattered.
At my old job, I met two of my best friends here. And my job would be much less sunny (ok, perhaps my whole existence) without shiftless badger by my side.
So here's a thanks- to work friends old and new. No, I won't sing you the Golden Girls theme song, but I'm TOTALLY TEMPTED. So enjoy that as a token of my appreciation for liking jobs that don't pay very much but are somehow money-centered. Go figure?!