Re: If you drink when you play in bars do you drink when you practice?
Indeed not - no alcohol, junk food or any kind of drug before playing at any time. I will only drink still mineral water 3 weeks before playing (only still mineral water because the gas in the bubbles diminishes muscle fibre function).
Once at the venue I bring out my prayer mat and engage in healthful prayer and pure thoughts until it's time to start biting the heads off chickens and setting fire to the kit. It's important to do the right thing.
As a brief digression from my path of self-righteousness, it should be said there is such a thing as state-dependent memory - where you are more likely to remember what happened when you were drunk when you're drunk.