[TSchmereL]

You should worry if your doctor says:

"Don't worry about your health, I can assure you that you do not have cancer. I did not complete a single test to see whether or not you have cancer, but I know that you do not have cancer because if you did, you would be dying right now and you are obviously not dying right now, so you certainly don't have cancer. That will be $100.00, please. Where shall I send the bill?"

[TSchmereL]

You should worry if your cook says:

"Don't worry, I can assure you that your neighbor has not poisoned your food supply."

"Although I know that your neighbor has publicized his intent to kill you by any means necessary, including by poisoning your food supply, it is just not possible. Your neighbor does not have access to a colorless, odorless poison. It is too difficult to get an effective colorless, odorless poison. And besides, your kitchen door is usually locked."

"I did not complete a single test to see whether or not your food supply contains a colorless, odorless poison, but I know that it does not because if it did, you would have died shortly after breakfast."

"So, please. Sit down and eat your lunch. Forget about your neighbor's intent to poison you, and think only of how difficult it would actually be for your neighbor to do it."

"By the way, what would you like for supper this evening?"

[RipSawyer]

How come you know so much about my doctor?