I often find it's quicker to write a bit of code than try and work out how a library would work, then deal with installing it and maintaining that installation as it gets updated. Of course, this depends on how much of the library is needed.
And when I have looked, at first I was surprised to see ugly code, things remmed out, variables declared and never used, debug statements still in production code...
Kind of shattered the whole "shrink-wrapped programmer on a pedestal" thing I had going...
It surprised me when I finally started working at a place with professional programmers that so many just didn't do it at all with code.