I think most of us lose our sense of wonder because as we grow older we see a lot of the negative parts of the world and we tend to hold on to those parts a little too tight. After holding on to something for so long it's hard to open up and forget what we have seen and see the positive in the world. I also think, that reaction is understandable. Time and time again people let their guard down start to have fun and live a little. But then bad things happen. Little kids get kidnapped and people getting lynched in the 21st century and more horrible things.