In a subtle way, and one that isn't your fault at all, you've become something of an obstacle to your partner's life path. You didn't intentionally divert them from their true calling; in fact, you really want to support them in everything they do, especially as you two have gotten closer as a couple. But you might focus too much on their past, which could impede their progress into the future.
You really identify with their past; maybe you had similar upbringings, or you had your hearts broken in ways that affected you similarly. You two talk about these experiences and you've allowed them to shape your values and the people that you've become. But whereas you want security out of this relationship as a result of your past, that might not be your lover's primary aim. And even if it is, providing that security for you might mean they can't move forward in their life. What if their dream is to join the Peace Corps and move to Africa? Or, less dramatic but equally valid, what if the right thing for them to be doing right now is simply focusing on themselves and their lives and not devoting as much attention to you? Again, you don't hold them back on purpose, but the effects are really just the same. Your bond is a comfort to both of you, so it's up to you to recognize this stagnation when it happens, and push yourselves to let each other move forward in your own lives -- even if it compromises the security of your relationship.