Doubt is to certainty as neurosis is to psychosis. The neurotic is in doubt and has fears about persons and things; the psychotic has convictions and makes claims about them. In short, the neurotic has problems, the psychotic has solutions.
I'm doing a lot of boogie-boarding now. It's actually better exercise, I get a lot more waves, and if I'm out in big surf, I can duck under the waves much easier.