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.
Lately I approach it from a somewhat Information Theory standpoint, and consider that possibly qualia in superposition are essentially not rendered as in one position or another until an interaction occurs that requires it to be in a singular state. In a sense, perhaps the superposition isn’t multiple states, but a single ambiguity that becomes resolved only retrospectively. (I imagine this might require temporary cosmological branching for isolated systems, until the point they resolve and re-integrate.)