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Drinkers 'ignorant' about alcohol
A survey suggests 77% of drinkers do not know how many units of alcohol are in a typical glass of wine.
REf. https://news.bbc.co.uk/1/hi/health/7399192.stm
If your body is used to a lot of alcohol it tends to make it harder for you to feel the effects of alcohol but that does not mean the effects will not be noticeable to others. Your motor skills are going to be effected no matter what. Yes your fine motor skills may be ok but trying to do complex tasks may not go as well as you think.
Yeah, I've seen this before. People become functions alcoholics. They convince themselves that everything is fine and they are functioning just fine, and they get used to being drunk so they learn to do some things. But everyone around them knows otherwise and can tell.