Worked with a guy that would fill a rocks glass with well whiskey and down it in one gulp after shifts. Not impossible that some Joe Protag could drink a glass.
Alcohol is a helluva drug. Most people can't believe I was drinking a twelve pack of IPAs and a bottle of wine or two and a few shots of vodka every day after work. Well, the wine would usually start before 5pm, but whatever. Sometimes I drank more, sometimes less.
Point being, most seasoned alcoholics I know could easily start their day with a quick pint of whiskey. I was quickly getting there as I would have to chug a glass of two of whatever I had, before drinking time actually started, to keep the shakes at bay.
After several years of that, a stout glass of whiskey is child's play.
(I quit drinking over a year ago and my body is still healing. It's going to take a few more years to get my gut working properly again and thankfully, my heart issues have all but disappeared.)
Multiple years sober here, keep it up, it only gets better the longer it gets. Most recently I’ve gotten into the best shape of my life, something I could never have done drinking at least a 6 pack and a pint a night.