The Stable One's Always the Craziest and Most Dysfunctional

In many years, I've never seen an exception to this rule:

The more stable, functional-seeming person is never the anchor in a relationship. The more flighty, neurotic-seeming one is always propping up the more sane-seeming one.

Except, of course, in movies.

It's hard to observe sometimes, because the true dynamic is often publicly disguised.