From youtu.be/fLJsdqxnZb0: It's not reality that shapes us, but the lens through which your brain views the world that shapes your reality.
Your external world is not predictive of your happiness. Your happiness is determined by the way your brain processes the world; your internal outlook.
See stress as a challenge, not as a threat.
Wrong formula for happiness: work harder = more success = happiness (problem is that more success = higher bar, forever keeping happiness out of reach). Correct formula: optimism = happiness = more productivity, energy, resilience = more success.
Positivity from Dopamine through gratitude, journaling, exercise, meditation, and acts of kindness.