Healthy?

So I have a thought that I'd like to share because it both bothers and confuses me and perhaps someone can explain it to me. Now, I've never been married, but I've been in serious live-in relationships with children where we might as well have been married. I have a few married friends who have clearly expressed to me that they don't need/want anyone in their life other than their husbands. Which, in turn, makes me feel as though, why the hell are we even talking then? If you don't want me in your life, why am I a part of it?
I look at these relationships as unhealthy. I don't respect them and I sure as heck don't ever want one. Why would I want my world to revolve around one person? I've been there, done that, and lost who I was in the whole scheme of things. I lost friends and when I needed someone to lean on, I had no one. I don't ever want to have my significant other have a business trip, or a guy's night and be upset because I don't have friends of my own to occupy me or because I can't stand to be in my own company.
I was in a relationship once where my partner worked long hours. He started working two jobs and I had let myself get into a rut where I didn't hang out with anyone but him. While he was at work, I would either be at work, or sit at home waiting for him to get home. I stopped hanging out with my friends, I stopped going out and doing things. I lost my own life that I had before we got together.
People might tell me that I haven't met the right person yet. They might say that when I find someone who is my soul mate, then I'll understand. I don't think that's the case. I think I've been in plenty of unhealthy relationships and I realize that it's healthy to have your own friends outside of a relationship. It's not healthy to cling to someone and say, all I need is you and I don't need friends or a life of my own outside of our relationship.
I asked an older, very happily married friend how she felt about this thought and she agreed with my thoughts. She said that if she didn't have her alone time, the time with her girlfriends, she wouldn't be who she is. Her husband has his fishing nights and weekend camping trips with his guy friends, she has her getaways with her girlfriends and standing dates with her girls. They have their own lives, but also do plenty of things together. They respect each other's "friend time" and this has led to a happy marriage of 20 years. I'd like a relationship like that. That's what I aim for. One where I DO need my friends in addition to my spouse and children. Friends can keep you sane and help to relieve some of your nags and complaints about your husband that you may not want to necessarily bring up to him. And I'm perfectly happy being single until I find someone with the same philosophy.