For me, it's simple:
1. I have my own space, and I have it decorated and arranged the way I like it. I don't wish to rearrange my place to suit someone else's taste and preferences. I did that for years; no more. If I want to spend an evening reading....I don't want to be criticized for it. And I like having control of the remote! :-)
2. I got taken to the cleaners 2 out of the 3 times I was married. It took me losing 2 houses, 2 cars, my parents' belongings, and my truck to teach me a very valuable lesson......never let someone else share my finances again. Even if I did break down and move in with Mr. Wonderful.....I want my money and expenses separate from his. It has taken me years to get my credit straightened out. No one is taking me down that road again.
3. Twice my children have been hurt and abandoned by men they trusted and cared about. Ok.....they're grown now....but the last husband did a number on my grandchildren before he left. Now I have great grandchildren. Nope. No one is getting close to them.
Freedom. Freedom to do as I please when I want anytime I want.
Peace and quiet. Don't have to listen to someone complain about me bringing in few blades of grass in the house and whine about always being so busy with stuff like laundry. I do the household chores and frankly, I never thought they were the big deal the wife made them out to be. It makes for a much nicer atmosphere not having to hear that all day long.
Don't have to walk on eggshells and have someone suspicious of me chasing every skirt in the county. I don't know how I ever put up with that in the past, but I sure as heck am not going to put up with that now.
No more questions without right answers like "Does this make me look fat?" "Which dress do you like?" "Where would you like to go?"
No more dealing with relationshippy issues with imagined slights, getting angry over absolutely nothing then angrier that I don't know why. I never have learned to read minds.
I have a number of really good female friends. I enjoy spending time with them and have a lot of fun. But a relationship? I just don't see that happening. I've gotten too smart.
Money and time! After ten years and having developed a lifestyle that is centered around my interests and needs, I think that I'd find it difficult to include another person into it. Plus marrying would cost me about half my income and I might feel trapped in the marriage if it didn't work out. Twice I've been married and I think that the odds are against a third marriage particularly since the last one was a good marriage.
I like the spot that I am in. No one to account to for anything I do or say.
The independence is hard to surrender, but there are mornings when I miss having someone to talk with over breakfast.