I'm like you and many PPs - I don't really get anything out of friendships. It's nice to occasionally meet up with someone for dinner and drinks, but I don't want anything deeper than that, and I steer well away from any sort of group outing.
People try to make friends with me sometimes but I keep them at arms length. I don't like the idea of having close friends. I often see close friends described as "The person I could pick up the phone and call at 3am if my partner left me" and I'm like... ugh. Fuck that. I would never call anyone in the small hours. Like, what for??
In my teens and early 20s I tended to have very intense friendships with other women where I was the "rescuer" constantly on-call to dive in and save them from whatever shit they'd got themselves into. Anguished phone calls, driving them all over the place because I was always "the friend with a car", lending (more often giving) them money, putting the shits up any bloke I thought wasn't worthy of them... It was extremely unhealthy.
These days I make sure I am capable of fulfilling my own emotional needs for myself. I don't feel it's fair to "lead people on" in friendships given that I won't really care very much about them.
I've been like this since I was a child. (Aside from the brief period of unhealthy intense friendships, which was at a time of great mental health problems for me.) I remember at primary school I had a "best friend" who lived round the corner, so we played together pretty much every day in and out of school. At the end of primary her family moved away for her dad's job. After they'd left I remember my mum asking me "Are you sad that Betty has moved?" I said no, not really. She said "But you must miss playing with her?!" I said no, not really. We remained penpals for a couple of years and I did go to visit her once when we were about 12. That was a drag.
OP you'll probably find when your marriage ends that you decide to never cohabit again! I've currently got my DS, who's 25, living with me, but he's moving out next month (please god it all goes through) and I cannot fucking wait! He's been back home the last 4 years, the 3 years prior to that of living alone were bloody bliss! I usually have a couple of reliable fuck-buddies on the go mind ;)