Beer with meals
Peter used to say that drinking water with meals diluted the food while it was in your stomach, making it harder to digest.
When I pointed out that he often drank beer with meals, he said that was different—he said that beer contains yeast and is sort of like bread in a way, so it actually helps with digestion.
(In case anyone’s wondering, five minutes of Internet quasi-research leads me to the conclusion that there isn’t a lot of good data out there about the effects of beer on digestion; some sites say it aids digestion, some that it hinders it. Regarding water, a Mayo Clinic doctor says that “drinking water during or after a meal can actually improve digestion.”)