Source: just about every mummy movie made. The example below is from The Mummy.
Lesson: when you know something you’re going to do will have a bad consequence, don’t do it. This especially applies to things that have always resulted in bad results. Remember how Einstein defined insanity – doing the same thing over and over again, expecting different results. Don't be insane.
If you want to see this rule violated the most, go to just about any gun forum and look for the members with the least number of posts. It also seems like forum trolls have whole libraries of Books of the Dead.
Examples:
Debating .45ACP versus 9mm.
Giving in to terrorist demands
Asking which is better training for the real world – USPSA or IDPA
Asking what would be the best handgun to carry in bear country
On a New York subway, asking “Mets or Yankees?”
For me, asking my son “So, when are you going to cut the grass?”