"Each problem that I solved became a rule which served afterwards to solve other problems." Rene Descartes
Me 'n' Rene - and every child in the world until someone convinces him that this is not a valid means and method. It works, though.
"What man has done, man can do -- or words to that effect." (a proverb apparently quoted by everyone from Charles Spurgeon to Saki, but heard in that form in the Katharine Hepburn movie Holiday)