A gem from Bird and Wadler's Introduction to Functional Programming

bird_wadler.txt

"A good way to tackle such problems is to consider a simpler problem first.
There is, of course, no guarantee that solutions obtained for simpler problems 
can be used directly in the problem which inspired them; they may only serve
to familiarise the solver with some of the features and difficulties involved.
Even so, the work is not wasted; familiarity with a problem is one of our most
important tools for solving it.  And often we will be able to use the solution 
directly or by adapting it."

!!!