Those are the good old times, when we have no worries whatsoever. You have no bills to worry about, no worries about where the next meal is coming from. But I guess we all have to grow up.
This is true growth in my own opinion. You keep the mistakes you have made in the past in your mind and make sure that you did not repeat them again.
The good old times was there to shape us for what is coming on the future but we weren't ready. We are have to grow up and that's the end of the story.
Mistakes showed that we are just imperfect and never perfect. If I continue to wish for time past, I might miss all the good things that is in the future.
That's life for you, I've learnt to start in time to teach my kids about it. Life is more enjoyable when we are smaller or when we are babies without worrying about anything concerning our next meal.
We all know that the opportunity to go back to the past will never be given to us. It shows how we are humans and so imperfect. The only that can help is to learn from it and avoid it repeating itself.
This is just the advantage of not being able to turn back the clock and time. All your mistakes and errors of the past stay right there.