The liver metabolizes approximately one-half ounce per hour, the amount in one 12 oz. Throwing-up, urinating, or sweating eliminates little to no alcohol from the body. As the blood alcohol concentration rises, the drug affects brain function which, in turn, affects judgement, emotions, coordination, and, if the person continues to drink, voluntary and involuntary muscles. As brain functions become impaired, some people say or do things not normally part of their behavior. People may become insulting, angry, or tearful.
Most people become happy because that is the reaction they expect.