I'm 46, never been married, not really looking, and probably never will be.
I grew up in a small town in Alabama that I really didn't like. Even at a very young age, I knew I wanted to get out into the big wide world, so I purposely never allowed myself to get tied down by relationships in high school or college. I like being mobile, and able to pick up and move wherever the career opportunities, or mood, takes me.
I'm also a VERY independent person, and I don't like "clingy" or controlling people. I don't like asking permission, or compromising, on what I can and cannot do with my own money. I figure I work hard for it, it's mine, and I'll save it, or spend it, as I please.
(already detecting a tone that's not very conducive to relationships?
)
If I ever did meet somebody, settle down, get married, etc, they would have to be willing to keep finances in a "mine, yours, ours" system. We would both fund the "ours" bucket to pay for joint things, but still have "mine and yours" buckets for everything else. They have full say over their bucket, and I have full say over mine.
One of the things that would make it very difficult for me to enter into a relationship with somebody who doesn't think this way is...I've built up a wall so high and so thick with respect to finances, that there is no way I'd allow any other person on earth to get through that wall, and have access to my finances. In the next 18 months or so, I might be able to walk away from the company I'm at with enough that I could (semi) retire and not have to do the 9-to-5 routine any more, which is something I've worked for all my life. And it's not something I'm willing to put at risk, for anybody.
Once I'm able to leave the working world, and finally enjoy all the things I've wanted to do in life for years, I'm not putting that at risk. If I meet someone who shares the same view, and we click, then great. But most people don't think that way, they want to share everything, and that would just put me at risk. Someone could walk off with everything I've made, or a nasty divorce could cost me half or more, etc. I know people who have been financially ruined because of relationships, and I will never put myself at risk that way.
Thankfully, I've never been the kind that felt it was mandatory to have someone along for the ride in order to be happy. If I ever meet the right person, then cool. If not, that's cool, too.