Naomi, when I met my OH he'd been on his own for 7 years and I'd not been in a serious committed relationship for 3 years. Suddenly being with someone meant not having everything your own way, having to give and take and all that jazz. Believe it or not, that can be difficult, particularly when you have been so independent. I didn't "need" a partner, but I felt I was ready to find someone, settle down and have a family.
You get out of any situation in life what you put into it and we both put a lot into our relationship. It's hard work at times, but worth it.