The rule of stupid is a simple concept - you are allowed to do one stupid thing at a time. More than one stupid thing at a time almost always results in trouble.
Trying to avoid doing stupid things is not always practical. Sometimes we simply find ourselves in situations that we look back at to say "well that was stupid."
The key to the rule of stupid is not having more than one stupid thing happen at a time. There's nothing wrong with being in the wrong place, but being in the wrong place at the wrong time or while doing the wrong thing or with the wrong people...that's where we've broken the rule of stupid.
Such a great concept that I learned from the parents of one of my athletes.