Fallacious yet widespread and documented beliefs courtesy of Wikipedia.
Alcohol does not kill brain cells. Early temperance writers promoted the idea that drinking causes brain cells to die (as well as the assertion that the alcohol in the blood stream could cause people to catch fire and burn alive). According to Queensland Brain Institute director Professor Perry Bartlett, there is no evidence that drinking alcohol leads directly to the death of brain cells. In fact, alcohol has positive health benefits when used moderately and new brain cells are generated on a daily basis. Alcohol can lead indirectly to the death of brain cells in chronic, heavy alcohol users whose brains have adapted to the effects of alcohol, where abrupt cessation following heavy use can cause excitotoxicity leading to cellular death in multiple areas of the brain.