During my bartending days, I kept seeing this guy in the pub. He would come in when most people would, the dreaded six p.m., after you finished work and came to get at least one before heading home. Well, this guy would get three or so before bouncing, and he'd always be alone. I don't know where he worked or what he did, although the one time we managed to chat, we had it interrupted by my manager. Regardless, I saw him almost every day for five months.
He came alone, he didn't talk to anyone, but simply read stuff on his phone. He had the occasional burger at times, but other than that, he kept to himself.
We brought in DJays, and had people jump around, on tables, on chairs, on the bar counter at times, except for this guy. He would place himself in a corner somewhere, drink his pint carefully, and then go.
I don't know what he did to have fun, but it sure wasn't through music, dancing, girls, or whatnot. Some people are like that. And that's a shame.