One answer is to be one's own moral compass - to decide right and wrong on one's own, with no playbook to fall back on. It creates a deeper, more flexible person - with more humility. One can't help but be humble when one's morals are based on on opinions and not a rigid dogma.
But choosing one's own path is full of grays. If one is deciding between two things with tradeoffs, how does one feel good about not going down the second path? I usually have been good at living without regrets, but I can't help but feel tugged in different directions right now.