That when you distill spirits - as in make rum or vodka or even homemade thunderbird - that the first bits of alcohol that come out when you tap your still is methanol and if you drink just 10ml of it you could be stricken blind and at 30ml you can die.
This is why people pour some of their drink on the ground as an offering to the gods, since if someone doesn't offer the gods their tribute they may be struck blind or killed.
That's science and anthropology bitches!