I do enjoy Carl Jung's poetic turn of phrase.
Jung differentiates the first and second halves of life, with the first being largely focused on developing an identity to succeed in the world. As adolescents we explore different social groups and activities, internalizing aspects of these things to form an identity. Our identity often relates to what music we listen to, how we dress, our hobbies
... See moreJude Star • The Paradox of Pursuing Happiness: Insights from Depth Psychology
In my experience of it, age has a tendency to make one’s sense of oneself harder to maintain, less robust in some ways.
Marilynne Robinson • Gilead (Oprah's Book Club): A Novel
Indeed, your world can break down precisely because you live on after the death of everything you love. This “death” can be much more painful and fearful than the prospect of your own death, not least because it is a death that you have to survive. Hence, as long as you are attached to someone or something that you can lose, you are susceptible to
... See moreMartin Hägglund • This Life: Secular Faith and Spiritual Freedom

Such a precept confronts him with life’s finiteness as well as the finality of what he makes out of both his life and himself.
Viktor E. Frankl • Man's Search for Meaning
Charles Eisenstein • Neither Hero nor Journey
As adults, however, we have a tendency to err too far toward exploitation—we become content to fall back on the stock of knowledge and mental habits we built up when we were young, rather than adding to or revising it. We get lazy.
Ian Leslie • Curious: The Desire to Know and Why Your Future Depends On It
Maturity involves accepting with good grace that we are all – like marionettes – manipulated by the past. And, when we can manage it, it may also require that we develop our capacity to judge and act in the ambiguous here and now with somewhat greater fairness and neutrality.