How come N+1 trivial tasks are expected to be accomplished in the same time as N trivial tasks?
An item you need will only go on sale after you buy it at the regular price.
If it can break, it will, but only after the warranty expires.
A carelessly planned project takes three times longer to complete than expected. A carefully planned project takes only twice as long.
A verbal contract isn't worth the paper it's written on.
Nothing will be attempted if all possible objections must first be overcome.
There's something wrong if you're always right.
You can't win. You can't break even. You can't even quit the game.
Investment in reliability will increase until it exceeds the probable cost of errors -- or someone insists on getting some useful work done.
All programs contain errors until proved otherwise, which is impossible.