Sometimes, one person in the relationship may even talk about marriage and then later back out of an engagement. I myself thought this happened because the person's feelings changed.
I found out eventually all my relationships were (for the most part) mutual.
When I say "mutual," I don't mean that the other person always put forth as much effort as me, but they usually felt the same way as I did inside. A person may have wanted to be with me and I wanted to be with him, but oftentimes circumstances got in the way.
Bad Timing + Not Ready = Frustration
Over the years, I've developed a simple formula for relationships. No matter how we felt about one another in any relationship I've ever had, it didn't help that either of us was not ready for marriage. Frustration stews in the emotions of two people when they want to be together but don't feel they can do anything about it.
Should It End If No One Is Ready?
I'm not saying people have to be ready for marriage in order to date. However, speaking from the perspective of someone who's had genuine feelings for over a half a dozen people in my lifetime, it certainly wouldn't hurt to be ready!
Now, I don't really like to dwell on the past and get caught in "if only I didn't...", but I can say this: If a person can at all stand being alone, it's better to travel, go back to school, get some hobbies and work toward establishing financial and emotional stability before dating one person after another.
What if I Never Marry?
So what? Who cares?! And don't worry about what anyone thinks, not even grandkid-hungry parents. No one should judge -- especially parents and friends who aren't even in happy relationships.