As someone who’s worked shift work all their life, what you tend to find is the longer someone has worked in the industry, the more likely it is that a lot of their friends have started as work colleagues and gone on to become out of work friends. Conversely, the more likely you are to drift apart from friends that are Monday to Friday 9-5ers.
When your working week finishes at 10 pm on a Tuesday and your day off is Wednesday, you’ll generally only find co- workers who are up for going for a good drink at that time. And your out of work friends big Friday night out isn’t quite so appealing when your back in work at 6 am Saturday.
So when you’ve got a bunch of people working together out on the piss, it’s only natural that work topics will get talked about more than if you all worked in completely different industries.
Doesn’t mean you don’t get boring bastards who won’t shut up about stupid trivial things work related. But they’d be boring bastards whatever they were talking about.