I think this quote is trying to say you need to be yourself and not follow the crowd. There are so many people who act the same because that’s what’s "expected" in society. If you continue with the flow and don’t go against it, you will end up being like all the rest without even realizing it. Hope that helped
Answer:
We can apply it to our own lives because we've all done mistakes and bad things in our lives but we can change our ways for the better like how instead of becoming a greaser Johnny believes that Ponyboy can become good in the world. It kinda shows how in life some people have done bad things but if they change their ways starting now they can still be part of the good in the world. I hope this helps :))
The author is J. B. Priestley