Any written criticism of another writer's editing or proofreading will itself contain an error.
Irreplaceable parts will always break or be lost, and at the worst possible time.
The probability of the loss or breakage of any part is directly proportional to the difficulty of getting a replacement part.
A dropped part will always roll to the exact geographic center of the largest available object for it to roll under.
Replaceable parts will only become available after an important deadline has passed.
Parts that are difficult to install will freely fall out on their own.
Parts that go in easily will be extremely hard to remove, and removal will be necessary to accomplish the needed repair.
The part you will need will be the irreplaceable part you threw away last week because there are no more parts of that type around.
What ever the customer has told you to prepare for the service call will be wrong.
The only thing you didn't check for a malfunction, will be the source of the problem, but you won't find it until you are called back.
The probability of arriving at the job site without a needed tool or with the wrong hardware are directly proportional with the square of the travel distance.
Any written specification you have been issued by the customer will be the old one that has since been revised.
You will always have what you need when the job is next to your shop.
Your best apprentice will quit and open a shop across the street and cut your prices. The one who is un-trainable will stay with you forever.
