Here are a few of Robert's Rules of fishing.
1. If you tell a friend that the fishin' is fabulous and that he'd better get down here fast, it is certain that the fish will not bite when friend arrives. Also known as placing "the kiss of death" on the bite.
2. When fly fishing and one or more people gather to admire your casting, a tailing loop is inevitable on the very next cast.
Can you add some of your own Rules to the list?