That's what happens when your life is handed to you on a silver plate. Working, struggling a little, raising a family, taking care of a house and other stuff keeps you busy and gives you purpose. But it could just be mental illness in this case, we don't know.
A lot of us are. It's hard to invent your own purpose. Was probably easier when purpose was thrust upon you (grow or find food or you'll die). I'm not saying life was better in the past. We live in fantastic times but it comes with different challenges. Finding purpose in life is a very real and difficult challenge.