Prim-drift is the erroneous impression that prims shift slightly out of place on their own over time. Actually, they don't. What's going on is that if a prim moves less than 0.005 metres (or is that 0.0005?), the viewer visually updates the position of the prim, but doesn't bother to tell the simulator that the prim has moved. When you come back later, the prim seems to be slightly out of position.
Also, the default attachment point for new objects in Second Life used to be the head. People would get objects stuck on their head frequently, especially if they were new (although it still happened to the experienced users as well)
By this time, I had a rough notion of what was going to happen with Bob in the next few strips.