For me it is the fact that our blood contains iron. I earlier used to believe the word stood for some ‘organic element’ since I couldn’t accept we had metal flowing through our supposed carbon-based bodies, till I realized that is where the taste and smell of blood comes from.
In high school my graduating class was 38. The one before us was 21, the one after 18.
Coincidently there was a massive blizzard that snowed everybody into their house for a week about 9 months before my birthday.