Rule #1,101

You know you're an old married person when you have no good ideas for what someone should do on a first date.

Rule #979

There is a careful order of operations when using Icy Hot, using the restroom, and washing your hands.

Rule #917

Webcomic Guest Rule #13 (from Saturday Morning Breakfast Cereal):

Don't invite Mathematicians to sporting events.

Rule #752

You have to celebrate Pi Day if your wife is a math teacher.

Rule #748

Some activities (such as motorcycle racing, extreme sports, and dare-deviling) are logarithmic in the amount they increase how cool you are. Other activities (such as martial arts, marksmanship, and artistic ability) are exponential in the amount they increase how cool you are.

Rule #690

One is the loneliest number.

Rule #607

Much like simplicity, complicatedness is subjective, not objective.

Rule #596 (End of Math Week & Guest Month)

Math Guest Rule #7:

Math is the purest discipline.

Rule #595

Math Guest Rule #6:

F.O.I.L.: not just for leftovers anymore.

Rule #594

Math Guest Rule #5:

If you multiply negativity in life, you get ulcers. If you multiply negativity in math, you get positivity.

Rule #593

Math Guest Rule #4:

Math is racist; only combine like terms.

Rule #592

Math Guest Rule #3:

Mathematics is about harmony & balance; treat both sides of the equations as unique individuals requiring equivocal love & attention (in other words, whatever you do to one side of the equation, do it to the other side, too).

Rule #591

Math Guest Rule #2:

Remember the order of operations.

Rule #590 (Beginning of Math Guest Week [co-written by my wife, Shelley])

Math Guest Rule #1:

Never divide by zero.