Have you never met "adult" fools? Have you never met teenagers who were thoughtful knowledgeable honest honorable and actively involved in trying to make the world a better place?
This ageism is bullsh**! How many old fools are that whom you personally know? Do you not know any teenagers whom you respect admire and feel will do great things? Sheesh.
Age doesn’t equal wisdom. Neither does knowledge (book smarts). Wisdom is something that must be actively pursued; it doesn’t just “happen”. To acquire wisdom, one must have knowledge AND put that knowledge to use.
Everyone makes mistakes. However, those who learn from those mistakes (so they don’t go about constantly repeating them) acquire wisdom.
Everyone has experiences in life. However, those who use those experiences to help/guide others acquire wisdom.
Everyone speaks and does things. However, those consider the consequences of their words or actions before saying/doing them (think first) , acquire wisdom.
All of this takes time, but it doesn’t have to take a lifetime.