One of the better comments on documentation appears in Ed Post's classic essay, "Real Programmers Don't Use Pascal":
If there is not enough schedule pressure on the Real Programmer,
he tends to make things more challenging
by working on some small but interesting part of the problem
for the first nine weeks,
then finishing the rest in the last week,
in two or three 50-hour marathons.
This not only impresses the hell out of his manager,
who was despairing of ever getting the project done on time,
but creates a convenient excuse for not doing the documentation.