You'd be surprised at what you can do with a hangover. Their is a certain state of impaired-zen that can be achieved with practice and force of will, if you let hangovers overrule what you do, it takes all the fun out of drinking in the first place.
I'm cutting weight at the moment so I haven't touched a drop in weeks, but once I am done with this cut there is a growler of
Brewdog Tokyo Imperial Stout (18.2% abv) with my name on it. I'll probably feel a bit under the weather the next day, but some hill work or deadlifts could still be in the offing.