Via Further Reading, I found this snippet from Tony Hoare’s 1980 Turing Award lecture (C.A.R. Hoare, “The Emperor’s Old Clothes.” Communications of the ACM, Vol. 24, No. 2, February 1981, pp. 75-83):
How do you build software that really works? Attitude is everything — you need a healthy respect for how hard it is to build working software. It might seem that adding this whiz-bang feature is only “a small matter of code”, but that’s the path to late, buggy products that don’t work.
Exactly.
Ed Bott 
On my first job out of college, my boss said this: “Programming is easy, all you need is a terminal and a chair.”
Even the best programmers have to scrap large portions of their code and start over. Nick Bradbury did so with FeedDemon 2.x when he found better ways to do more. The same argument Hoare makes can also be said about writing a book, don’t you think, Ed?