I think we all go through a similar process of understanding where we fit into the world and trying to find a purpose. I also believe that it has a lot to do with our bodies own chemical development. It's comforting to know that the same thoughts have been had by others; there was a time when I used it as a muse for writing very overly sentimental and dark material - often folk songs.

Any written material, once written (the writing being part of that writer's catharsis and experience), is only really then meant to be read by someone else, and so it becomes the reader's catharsis and experience. Although, there are often times, when I revisit my older poems and see them completely differently - it's all subjective at the end of it all. :)