Here is my experienc:
In HS, I never drank- not even once. I was a 2-time All-State wrestler in the state's largest division, and I wanted to go on and wrestle in college. I was a 119 lb. wrestler, and I refused to cut weight. I was benching my body weight for sets of 12 or more starting when I was 15.
In college, I wrestled Division I, starting almost every match as a freshman. I went on a lifting binge before and after each season and got up to 132 (as a freshman) before cutting to 118 and 126 (those weight classes no longer exist). I did this for my first couple of years. After I got SICK of that, I moved up to 133 for my Senior year, and I really lifted seriously, still NEVER drinking. I had part of one drink on my 21st birthday- that was it.
At 22, I finished wrestling and graduated. I started drinking from time to time, gradually doing so more often while I was in law school. The whole time, I lifted like crazy. By the time I was up to 135 lb., I was repping 225 on bench 2-3 times. I was also power-clean-and-pressing 205.
As my drinking and lifting continued, I never saw much of a detrimental impact. As a matter of fact, when I made an assault at breaking the goal of benching 2x my body weight, I STILL drank any time I went out- which was 2-4 times a week. I drank beer and/or liquor, and as long as I got enough sleep and otherwise ate correctly, I never saw a drop in performance. Right through breaking the 300 lb. bench plateau, I drank. Through 315 lb., I drank. I was even in competetions and still drank regularly. Now, I was eating, sleeping, and training CORRECTLY to be able to continue these gains, but you CAN drink alcohol- even in copious amounts- if you otherwise treat your body well.
Now, 5 years later, I found that drinking is MUCH more impactful on my lifting. Last year, when my wife was pregnant, I did not drink out of respect for her inability to drink. My lifting improved by leaps and bounds during that "dry" spell. Now that I am back on the bottle (from time to time), moderation is the key.
So the take-home message? If you train your @$$ off and eat & sleep well, you can "outrun" the detrimental effects of alcohol- for a while. At some point, though, it will catch up to you and you will have to modify your behavior if you want to see maximum results in the gym.