The universe starts off with the Big Bang theory, and the first thing that emerged from the Big Bang is essentially hydrogen and then helium. And that's what combusts in stars. Finally, stars implode, and they build heavier elements out of that. And those heavier elements are reconstituted in the heart of other stars, eventually.
When I was 14, my dad came home one day and told us he had cancer. It was looking pretty bad. And I remember him saying how afraid he was that he hadn't gotten to do the things he wanted to do during his life. He had surgery and survived. And he's still alive today, thank God. But it made a big impact on me.