Regardless of the source, when alcohol enters the blood system the effects are the same. Many think a beer contains less alcohol than a standard mixed drink. This because it usually takes longer to drink beer than it does a cocktail. And beer is much more filling. Also, cocktails sometimes are mixed stronger than a standard drink, making them equal to two normal servings of beer or wine.
Alcohol affects people differently.
A heavy drinker may show few physical signs of drunkeness, but the effect on the brain is the same as it is for a light drinker. A motorcyclist showing no outward signs of intoxication may still be unable to ride safely. A physically large person can have two drinks and only be affected moderately, while a smaller person could become quite intoxicated on the same amount. One person's BAC is at at any level, it can only be reduced by allowing the liver time to oxidize the alcohol. Showers and coffee don't make you sober.