Being happy means you'll never feel like crap
It's no coincidence that a lot of these myths are cliches from fairytales, and nowhere is that more evident than humankind's steadfast belief in happy endings. No! Not that kind!
The "happily ever after" stuff just isn't real. To be human is to feel, and it's a guarantee that you'll feel disappointment, loss, anger, guilt, sadness, fear, conflict, embarrassment, frustration, and so on and so on. These feelings are universal; happiness is about being able to make space for ALL these shitty emotions, not just the positive ones. They’re not a sign of brokenness or pathology. They mean you’re not a robot or a psychopath. Nice work!
True happiness doesn't need any validation from external people or achievements
Just because achieving your goals won't bring you happiness doesn't mean that a total detachment from the world is a sign of true contentedness. Humans need connection, and it's not a sign of unhappiness if you happen to want a family or really take pleasure in getting a promotion at work. Don't confuse this with a romantic connection, though -- the essential thing here is that connection makes you more human, whether that's through platonic friendships, volunteering, stamp collector swap meets, a backgammon club, or whatever you enjoy.