There was an analogy that I really liked, so I'm going to rip it off and play with it some more. The basic premise is that during times of difficulty and challenge in relationships, like a tree, it is good to be deeply-rooted, to dig in and draw from the foundation. When things are going well, spreading one's branches and reaching higher towards the sky makes sense.
One of the things I love about having a great long-term relationship, like the one that PG and I share, is that the root system of our relationship is deep, wide-spread, and pretty comprehensive. It reaches throughout the vast majority of my life as an adult person, in ways that are not apparent from the outside, but are known in the many small gestures, habits, and the way we can read each other's body language as an unconscious competence.
There are the times when I can rely on my "root system" to do some rapid growth, to be able to reach a new spot that would be a bit scary if it was just me. Spending some time swaying in the upper branches can be exhilarating, but the comfort of coming down to earth is also satisfying in it's own ways.
Let us not forget those who join us on the journey! There have been many times where I have allowed the connection with S to support and nurture me to feel more comfortable with PG going through a growth phase and vice-versa in various directions.
The spreading of branches is showy, and gets a lot of attention, but it is the base, within oneself and/or within existing partnerships, that allows that growth to happen. Forgetting to nurture the base is contrary to the goal of being to able to reach higher without toppling over.