A horse-drawn carriage strolled past a stone mason at work when suddenly the passengers looked out in amazement - when, with one seemingly hardy wack, the stone mason cracked a massive boulder with a single blow.

"Gee, how strong you must be and how did you accomplish such a feat with one wack of your axe" asked voices in the carriage to the stone mason at work.

"I wacked this stone 100 times before it broke. Thus it was the 99 times I wacked it that you did not see that gave it the force that appeared to have yielded on the 100th attempt. Suffice it to say it was the accumulated wacks before that ultimately yielded the final crack."