As my general state of health has improved, the difference between how I feel when I'm hungover and how I feel when I've just worked out has widened. So I notice hangovers and lack of sleep more. Which causes me to drink less and try to get more sleep, particularly on weekends.
To restate it: My average health initially improved because I raised my "max". The resulting increase in variation caused me to notice and raise my "min".
Interesting example of positive reinforcement.
