When you become dependent on it, or when it starts affecting your health.
A couple of years ago I used to go to a pub near work with mates a few times a week.
The days when they couldn’t make it I started to go on my own. It was a quiet little pub, with friendly bar-staff and a few regulars that I got to know. It kinda became addictive.
A few weeks of this and I started to become dependent on it. I couldn’t wait to get out of work at 5:30 and nip across the road. I was having around 4 or 5 pints a night, which isn’t excessive in some peoples view, but was for me.
Mornings I didn’t feel too good, weight was piling on, I wasn’t eating proper dinners.
Thankfully the pub shut down so I stopped going.
It was only really at that point that I looked at myself and realized I’d become a rather unhealthy chap, so I made a few lifestyle changes and did more exercise and reduced drinking. I now have a hatred for hangovers, so tend to just have a few drinks on friday night and that’s all.