Hard lead in a mechanical pencil will turn soft if the pencil goes into the wash. It gets softer if you wash it twice. If you're used to writing with a particular lead hardness, the effect can be disconcerting.
I do most of my off-line Perl scribbling with a $4 Parker mechanical pencil. It has a nice rubber grip and a generally good feel. And I tend to leave them in the front pocket of my pants, and hence to the wash.
I was musing, while culling my collection of writing implements, that certain pens and pencils associate with past projects. I got through two big projects using a fairly expensive Parker Rollerball, but gave it up when Parker stopped making fine-point refills in blue. An unnamed rollerball got me through a (thankfully) short VB project. I used a particular fountain pen, filled with red ink, to review a shelf foot of specs on another project. Perhaps the lingering pain of that project is why I don't use that pen anymore. A set of drafting pencils date back to my UI days. And from early history, a collection of Pilot Razor Point pens was used when scribbling out PDP-1O assembly language on greenbar (line printer paper). These went into the dustbin, after a few moments of nostalgia. And in the back of one drawer was a cheap Parker pen that got me through CS classes in college.
Looking around, I'm sometimes amazed how little attention some people pay to the implement they use to write. It's like kinesthetic tone deafness. The idea of using whatever cheap office supply store pen happens to be stocked in the company supply cabinet give me the willies.