In my experience happiness begets happiness.
I'm quite happy being by myself on a regular basis. Sometimes I need human contact. I love my boyfriend and am quite happy with him. I'm even happier now that I have Possibility and his family in my life.
“Laugh and the world laughs with you; Weep, and you weep alone; For the sad old earth must borrow its mirth, But has trouble enough of its own”
Ella Wheeler Wilcox
For me poly is about having needs met by one partner that can't be met by another. If I want a quiet movie night it's Possibility all the way. If I want conversation it's Breathes. There's more to it than this paragrapgh suggests but I can't quite put my finger on what, exactly, yet.
It also has something to do with compersion. When Breathes or Possibility are happy then I'm happy. When I'm happy they're happy.
Poly just makes the wholeness MORE whole, if that makes any sense, lol.