Yes, I agree completely. Take leftpad, for example.... And more seriously, there are times when factoring out "common" code makes the code significantly more

Yes, I agree completely. Take leftpad, for example.... And more seriously, there are times when factoring out "common" code makes the code significantly more complicated, and often turns your common code into a morass of special cases as your application progresses, and these cases that looked "the same" end up being "not quite the same".