I used to think that everyone was pretty much the same. Now, I realize that the heart and intellect of man appears in all shapes and sizes.
I used to think that I was glad that I did not have to relive my past, because I didn't want to go through those hard times again. Then I wished I could go back to do things differently. Then I wished I could go back and do it again knowing what I know now, because I believed I could help people more than I did. Now I realize that the interactions I had were planned by an all-knowing God so that it the ideal time for those interactions to happen for the greatest good.
I used to think that everyone thought and felt like me. I don't think that anymore. Not a day goes by that I am not given some stark example of some base motivation in someone else that was hidden by my naive optimism, and yet it has taken all of my 35 years (ok, maybe 18 years where I've been paying attention) to finally believe that mankind is as fallen as the scriptures say.
I am astounded at the depravity of man on the one hand, and astounded at the irregular number of good people God has put in my path on the other. While I wish there were more people I could look to as resources, and although the tail of the path of truth is one of abject loneliness, I am glad that there are some people in my life who are good people, as far as they know how to be. Given the proportion of bad to good, I feel lucky in the number of good people I know.
I used to think that if I could go back and time and meet myself at about 15, I could dispense sufficient knowledge that I could catapult myself ahead by a good decade in progress, and do so much more with my life. Now I realize that if I did do that, I would simply smile at my younger self, and have absolutely nothing to say. I realize that I already was doing the best I could given where I was, and God was already playing the role of the person who knows the future, giving me all I could handle exactly as soon as I could handle it. Knowledge requires experience, among other things, and experience requires time. Even when the other conditions of obedience and desire are perfectly maximized, the process requires time.