We are made up of fears
We are literally made up of fears. Even all so-called positive words have fear embedded at their core.
Take confidence: you only need it when something you desire is at stake, like an interview. You don’t need "confidence" to talk to a friend.
It is the same with happiness; we try to lock it down because we are fearful of losing it. We love a person, so we secure them using marriage.
The mind is just the collective sum of everything I have a dependence on - money, power, fame. When I say "I am rich," I am defining myself by that dependency. We feel we will finally be fulfilled if we get these things, and that without them we are not much.
Why? Because of our wiring and conditioning.
We are so terrified of the emptiness underneath that we build an identity entirely out of the things we are afraid to lose.