I am whole within myself and my partner is whole within himself/herself.

Two whole people in a relationship does not mean two self-sufficient ones. Nobody is whole in the sense of needing nothing.

It means something closer to structural: neither person is the other's only load-bearing wall. You have your own friendships, your own reasons to get up, your own opinions about things they find dull.

Which is exactly what makes leaning safe. Someone who can stand alone can be leaned on hard without the whole arrangement coming down. Wholeness isn't distance from each other. It is what makes closeness survivable.