Roy Pea coined the term "superbug" in 1986 to describe the belief many novices have that computers can understand our intentions in the same way that people do. There's a similar superbug in education: the belief that if someone knows how to do something, they also know how to how to teach it. It's really hard to convince people that it just ain't so. Pointing them at evidence doesn't work; if anyone can suggest strategies that do, I'd be grateful.