The relationship between alcohol and ego?

Alcohol lowers inhibitions, and in doing so is likely to bring out all sorts of traits that were formerly repressed. A quiet girl becomes the life of the party; a self-effacing man becomes a braggart.

These sorts of things are often the reverse of what they seem. The bragger may be covering up a feeling of low self-worth, the party gal her feelings of insecurity and not fitting in. When people drink chronically, they are liable to become their own legends, in their own minds, leading to the grandiOSity and ego that we associate with some of our acquaintances who drink a lot.