Having completed 5 Massive Online Open Courses (MOOCs), I was starting to think of myself as kind of hard core. What a deluded putz! It turns out that more than 900 people have completed ten or more Coursera courses, and 100 more than twenty. A single mother of teenagers in Amsterdam has done 30 MOOCs, despite having a day job. None of these people have taken any for credit, but they all find the MOOC addictive, like certain online games after which they were named. Others are rushing to take as many courses as they can because they are afraid the MOOCs will disappear.