There's a lot to be said about humanities value models of life. You aren't here to acquire wealth, build a career, or do anything that society may call normal and successful. Yet, most of us blindly chase this dangling carrot, often the price is a life we forgot to live truly for ourselves.
Being youthful means to be free from the shackles of normality that society uses to tie us down. Youth often sees the dilemma, they see the mess our false models have created for the planet and they begin to initiate their own internal struggles between their dreams and the human system. They go seek help from health professionals but the issues are systemic to society itself, not the individual.
By the time they are mid 30, most will be married, have a child, have a mortgage and a decent car, along side a job or career, but probably ended up suppressing their dreams and their truth to achieve all that. Now they have dependants and debt and there's not a huge amount of space for change that they are yerning for. They wanted to live abroad, learn foreign languages, busk as a musician in the streets and perform in jazz bars, but now they simply go to work full time, and maybe once a week and on the weekends work on a little side project to keep their creative juices flowing.
We are a civilization that has given into fear and would rather choose the guise of the security and materialistic rhetoric over the liberation of knowing that life is delicate, precious and could be gone tomorrow, so you may as well live it completely in truth, rather than in someone else's narrative.