Comment by ticulatedspline

it's not success aversion it's because 10% of the work is 90% of the work.

Basically every project it's easy to "rough in" about 90% of stuff. but the devil's in the details and most of the work is that last refinement. be it code documentation,testing,cleanup refactoring etc in a tech project or sanding/staining furniture, or whatever. typically at the 90% point you're not even half done as far as labor is concerned and those last bits are the most tedious and least rewarding.