Then, like a lot of kids, I had a short-lived pet and I thought I almost had it, then. It was ugly and awful and why would a good god do a thing like this? And then came living on a farm, where animals dying was normal, and explained. But people? Still clueless on that front, and then a... boy I really had a heart-on for died, and I turned into an emo little turd - I took his death as a personal insult from a spiteful demiurge and a source of torment from the world around me to punish me for some unknown crime.
Then my grandmother died... and I still didn't understand it completely. I understood the mechanics, I understood the biology. I did not understand the psychology - I was a pretty newly minted witchling, and even though she wasn't in her flesh, her spirit was never absent, always visiting in dreams and leaving the scent of her perfume around. She was in 'heaven', her suffering was done - Why are we crying? She was kicking it with big J and the Angels.
But I felt utterly, utterly, guilty for not feeling really, really, really bad. Now, another fifteen or so years later, my last grandparent has left the world. And I get it now. It took me a lot longer than most to leave the swoon of childhood innocence and skillful, wonderful, constructive self-deception to simply mourn.