This question is a very useful lens for examining your life.
Will you regret not taking a risk to pursue your dream?
Will you regret having tried if it doesn’t work out?
Will you regret switching careers to something that excites you? Even if it means ignoring the sunk cost of years of schooling and experience?
Will you regret not spending more time with your family?
Or letting others decide things for you?
Will you regret staying exactly where you are now?