> But the last 1% is exponentially harder than the previous 99%. Also, sometimes (often?) you can quickly make a lot of progress using the WRONG methods that a

> But the last 1% is exponentially harder than the previous 99%. Also, sometimes (often?) you can quickly make a lot of progress using the WRONG methods that are completely useless in the remaining 50% or more of the work. Then that field hits a dead end and is mothballed until a decade or so later when sometimes dares to restart it from a fresh perspective.