Age

"How old are you" I ask. A reply in years, usually alot less than a hundred, is given. I would have given a similar reply, until my science tutor put a very interesting idea in my head; We've been here for trillions of years. The atoms that make up our body have been in existence for God knows how long. A Carbon atom in your arm might have been part of a dinosaurs ages ago or a piece of shit. Scary. I don't have much to say about it, but I found it pretty darned interesting.
I knew about the conservation of mass and all that, but I had never pondered about this. Yes, it is insignificant and boring, but I found it pretty interesting.