From Raj Jain's Book: The Art of Computer Systems Performance Analysis

If you can't convince them, confuse them. --Truman's Law.
No experiment is ever a complete failure. It can always serve as a negative example. --Arthur Bloch.
It is impossible to make anything foolproof because fools are so ingenious. --Arthur Bloch.
Experiments should be reproducible: they should all fail in the same way. --Finagle's Rule.
To estimate the time it takes to do a task: estimate the time you think it should take, multiply by 2, and change the unit of measure to the next highest unit. Thus, we allocate 2 days for a one-hour task. -- Westheimer's Rule.
Work expands to fill the time available for its completion. -- C. Northcote Parkinson.

Some more...

In theory, theory and practice are the same, in practice they are not.
Murphy's law and others...
Each generation has its few great mathematicians, and mathematics would not even notice the absence of the others. They are useful as teachers, and their research harms no one, but it is of no importance at all. A mathematician is great or he is nothing. -- Alfred Adler
Quoting one is plagiarism. Quoting many is research. -- annonymous
Research is what I'm doing when I don't know what I'm doing. -- Wernher von Braun
A good proverb website - The Psycho Proverb Zone

To be continued... More Wisdom collected at Uni-Vienna, Austria.

Special thanks to Johannes Luethi!.