As I See It...

If you think you can't... you won't.
If you won't... then you don't,
And if you don't... then you are aren't.

Aren't stepping outside the box.
Aren't being spontaneous.
Aren't living life to the fullest.

What you are ends up being...

Missed opportunities.
Excuses.
Regret.

Should of, would of, could of.