In 1999 we bought a house. It had a locked safe embedded in a wall and the seller did not know the combination - the house had belonged to his parents who had passed away. When we started remodeling the house we used a jackhammer to pry the safe from the wall, planning to discard it. But, in a moment of inspiration, I loaded the safe on a pickup truck and took it to a local locksmith to see if he could open it. The locksmith took a walk around the safe and reported "the combination is xxL,yyR,zzL." I was astonished. Until he showed me the secret: there was a piece of paper taped to the back of the safe.