I guess here's my contribution:
At the end of every hallway is a man with a shotgun. You can't get past him; he has the fucking shotgun; he will win.
You will try to stay at the other end of the hallway as long as you can. Yes, this is the right thing to do.
However, at some point the clock strikes and the man with the shotgun picks up his Bible and blacks his boots, oils his shotgun and cocks it, and comes down the hall.
Experience is knowledge if interpreted correctly, and is the only real value in life, because the only real commodity is time.
The quantum of experience is also time.
Adults have one salient advantage over youth: they have seen how actions, ideas and attitudes have worked out over a lifetime.
So what seems like you get away with it today and next year and a decade hence... may be death in two decades. More than death, it may be the true horror of adulthood, which is regret.
Regret is what makes you want to walk on down the hallway early. It's the knowledge that with the same resources, in the same time, it could have been elsewise -- and better, since you've seen how each approach worked out.
Humans, we're like a sheaf of wheat, each stalk choosing a path. When the reaper comes, we know how each approach worked out. And I don't mean theoretically: we know in practice, literally, without doubt. That's regret and the man with the shotgun in one, because you can't go back. You can't redo an experience because the experience is context and your own knowledge and how new things were to you (imagine being able to listen to Pure Holocaust again without ever having heard it -- you're both excited and afraid you won't see in it what you do now).
Thomas Wolfe is right: you can't go home again. Siddhartha is right: you can't step in the same river twice. Arjuna is right: we are all symbols of the meaning of a time, not the other way around!
If life is a tapestry... if life is a symphony... if life is an equation... context matters more than the tangibles. The pattern is all. (Understand that and you've mastered idealism. Hint: takes about 11 years, which is why 33 is the age of prophets.)
You can't get your innocence back.
You can't have another first love.
You can't redo the decade from 18-28.
You can't get your virginity back.
You can't change a pathology once it has been with you for two decades.
Decisions are decisions; decisions are done. They are the vanguard of the man with the shotgun. When they have done their work, he comes. In most cases, his targets are compliant.
If reincarnation exists, it is so you can try again and have a first love that triumphs, or listen to Pure Holocaust the first time again and run screaming down the street: I get it, I get it!
All is all and all is now, all is one and one is now.
At some point, you start to want to stop fucking around with the dead pathways. Difficulty: people who have taken these pathways 90% of the time are going to face a choice -- (a) admit you were wrong or (b) defend what you did as if it was right -- and they'll pick option (b). Hippies, I'm looking at you. Aging punkers, even most aging metallers.
The point is that while there are experiences that fit every part of life, there's also always stupid and not-stupid. And really, doing things the smart way has more in common between the ages than it does different. What's smart at 16 is smart at 36 is smart at 64.
The sooner you find transcendent, brilliant, abstract and realistic truths, the sooner you step ahead of error.
Maybe, or it could just be, youth culture music is crap. Dubstep is crap, techstep is crap, most metal is crap... it's all designed to keep you busy in confusion until they use you for something. Aim higher.
You cannot beat the man with the shotgun. What you can do is make the hallway come alive.