“Inch by inch, life’s/it’s a cinch” is a saying cited in print since at least the 1950s. Often added is “yard by yard, life’s/it’s hard,” also cited in print since the 1950s. “Mile by mile, life’s/it’s a trial” has been cited in print since at least 1977.
Robert H. Schuller, the pastor and author who began the weekly Hour of Power television broadcast in 1970, has popularized (but did not originate) the “inch by inch, anything’s a cinch” saying. The “inch by inch” saying has been used in business and in government as a method to solve problems. Source: http://www.barrypopik.com/index.php/new_york_city/entry/inch_by_inch_its_a_cinch_yard_by_yard_its_hard_mile_by_mile_its_a_trial/