It's been a combination of both choice and inability to choose, if that makes sense(?) Our 10-year-old daughter has had two brain tumors, the first when she was 3, and that has kept us together.
I have a inner voice that likes to confound me!--when I make a decision to stay with Ron, the voice says "You need to be away from him to grow and be yourself." And when I make the decision to leave Ron, the voice says "The work you need to do on yourself is the issue, not the relationship."