In all seriousness, I found myself wondering about those numbers before; but consider that there's on the order of 10^27 atoms in your body. So, if we assume a trillion neutrinos in your body, that indicates that for each neutrino in your body, there are 10^15 atoms - that's one part per quadrillion! A machine capable of detecting neutrinos in your body would need to be _unimaginably_ sensitive, before even considering the intrinsic difficulty in detecting them due to low mass and neutral charge.