What is existentialism ?
Existentialism is a notion that we are free to make our own choices. This freedom can be scary, and to protect ourselves we pretend to not have a choice.
A lot of people end up unhappy because they have not sat down and faced their own view of the world and carefully examined whether what they are doing is getting them to what they truly want. Which of course requires an understanding of what you actually want in life.
Taking the time to answer these questions is scary.