Why is it important to say "thank you" when someone helps you, and what are some creative or meaningful ways to express gratitude?

Reality might be an illusion, but our choices have consequences, and changing circumstances have real effects on our well-being. How do we reconcile these seemingly contradictory truths?
How does a childhood spent observing rather than speaking influence the way you read people as an adult?
What is it like to feel you have to optimize every part of your life?