A bit of science information for us to puzzle over today: My ferritin level is low. A normal ferritin level is about a 100. Mine, right now, is a couple of ticks below 20. So what exactly is “ferritin,” kids? And why do we care about its so-called “level”? I have no idea what the word ferritin means; I was pre-med for a tad less than 1.5 semesters in college. Chemistry is what finally drove me off. Though I do now know that ferritin has something vaguely to do with iron (thanks, WebMD). And I also know this: if your ferritin level is below 20, as mine is, congratulations,…