Why Is Raymond Plank's Memoir Called a Small Difference?

David Senra reads the introduction of Raymond Plank's memoir A Small Difference. Plank writes that at about age 10, on a walk, his father dropped his hand, put an arm around his shoulder, and said he had found it very useful to try to make a very small difference on behalf of others. They never discussed it again. Looking back from his 90th year, Plank says the line was still fresh nearly 80 years later.

The second cornerstone was a postcard his mother wrote a few days before she died at age 47, when he was 15. She wrote that the 15 years they shared had been glorious, that he was fine and unselfish, and that her pride would go on if he kept his head up and his courage and faith high. She died of a blood clot to the brain after a routine appendectomy, only hours before he was to drive his father to the hospital and bring her home.

The book's account, as Senra reads it, says the two cornerstones had much to do with the career Plank chose: self-employed, on a smaller and riskier initiative, rather than work for a large company. The same introduction says Apache Corporation was founded with $250,000 in 1954, and by mid-2008 the $250,000 had become $50 billion.