There's nothing wrong with butterflies, they can come and go. But I think a mature relationship doesn't depend on them. Did your previous relationships all end when the infatuation did? A "business arrangement" is not the "more solid" thing I was referring to.

My previous relationships ended for various reasons not related to infatuation. Mostly because I went to college across the country. And then moved back across the country after college ended. That ended two relationships.

The "feel sad when she's not around" part is not something I envy or even consider good as a long-term characteristic of a relationship. My wife and I love each other deeply, but we also don't suffer during short absences. We want each other to be happy, but we don't need each other to be constantly present.

It's not short absences that I'm talking about. I'm talking about being away from her for months at a time. I can't be around her for more than 6 months in a year because if I stay in NYC for over 6 months a year, then NYC considers me a NY resident. At that point they'll charge me 13% extra in income taxes, which with my income would be in the hundreds of thousands of dollars extra.

Are you capable of being happy when she's not in the room? Of course. This is what my life is like when she's not around.

Does your happiness depend on her being happy, or does it depend on her being present for you?

There's no dependency. Her happiness and my happiness is independent. I just miss her when she's gone.

I view a mature relationship as being based more on an active desire to support the other person than on an emotional dependence on their immediate presence.

I agree. But again, there's no emotional dependence in this relationship. You can miss someone and feel sad that they're not around and still be happy at the same time.