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.
Yes I knew about that and I’m glad that doesn’t make it crazier for me, instead it makes it easier to accept. If it were something that happened only after hitting some arbitrary speed value I’d be a lot more mentally damaged
To be fair the only ones that don’t get mentally damaged at all with this stuff are theoretical physicists. After all being crazy makes you immune to further madness.