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.
Also, in this simulation are the customers arriving in equally spaced intervals or is random arrival time within the bounds assumed?
In the linked article they are arriving randomly. It takes 10 minutes per customer and they arrive every 10.3 minutes.