Long time A's-how can they appear to be sober when they are drunk?
When my RAH was 5 or more beers in, he showed all the normal signs of being drunk...slurred speech, unsteady/stumbling, slow reflexes, incessant talking etc.
My brother in law is an end stage alcoholic. His doctor can't believe he's still alive. He wakes up at 5 am to have his first beer. Oddly, his speech isn't slurred, he walks normal, he just seems normal. Except at night, he runs his mouth like your average alcoholic.
Which is why my father in law thinks he's quit drinking. Or cut down. When I clean at my FIL's house (where he lives) I see the beer cans in the recycle container. Lots of them. There would be more but my BIL disposes of them on the way when he walks home from the store, or drinks it outside the store. He also likes his vodka.
He has had most of the family fooled for quite some time now. Everyone says he's cut down and he's never drunk anymore. I say it's been so long since he's been sober, how would they know what he is even like sober? They are in denial, I dropped that argument many moons ago.
But really, how can someone who has been an alcoholic for 30 years not show the normal signs of being drunk? My mind is baffled.