each person is different, for some alcohol causes sleep, for others it only suppresses the frontal lobes and balancing organs...and many more... and may be when it comes to you, alcohol doesn't just shows its affects in brain, it interacts with several different molecules including hormones (after all, alcohol is just another chemical that is waiting to react when the conditions are right)...anyways, if it interacts with hormones, it may show some effects even when you're hungover.