I called myself a commitment-phobe in my 20s but I'm not sure I like the phrase now.
What I meant was that settling down in a conventional relationship held no appeal for me; and the freedom and independence I had outside a relationship was something I didn't want to curtail. I also couldn't stand neediness, possessiveness and jealousy - a lot of people really seem to need a performance of commitment to feel secure in a relationship. I didn't need that and I didn't want to provide it.
I also had very high standards - if a man didn't actively enhance my life I'd get tired of him very quickly. I liked casual sex and found it easy to move on.
There was definitely an element of being extremely guarded about letting people in and being vulnerable. Obvious roots in my childhood there. I've never felt the need to change that though, I'm happy with how I am.
So I was long-term single and my casual relationships never lasted long, so I guess that's why I was labelled a commitment-phobe.
When I met DP, I basically found someone on my wavelength about all the above things. He didn't require anything more than I could give. He probably doesn't perform romance to the standards a lot of MNers expect, but I perform it even less well and neither of us especially want it.
I spent the first eight months of the relationship enjoying it, but ready to walk away the minute it wasn't working for me. And I could've done that without a backwards glance. Eleven years on it hasn't stopped working for me at any point so I'm still here. That's all a relationship is really. Are you compatible and is it working for you? I don't know if those things are forever, but they're more long-term than I imagined they could be.