In all reality when is it ever ok to drink?
You never know when you're gonna get a phone call and have to immediately go help someone. You never know when a family member is going to fall down the stairs, dump a pan of hot grease on themselves, or accidentally lacerate an artery with a paring knife, and you're gonna have to deal well with that....and then drive. The night that the tornado hit here I'm sure glad that I was sober, because it took some seriously quick thinking and coordination to keep us all alive.
I guess that people that start drinking at 5:00 every day, and pass out by 11:30 just assume they have no responsibility to anyone should something happen that requires all of their skills. My mom was a heavy drinker and I grew up knowing that I couldn't depend on her for anything. That kinda sucked.