This amusing picture, of an anti-drug propaganda pencil whose message is subverted simply by sharpening it, been doing the rounds. The truth is stranger than some of the fictions that accompany it: it was sent to schools and recalled only after a child noticed the problem. From a 1998 New York Times story:

As a result of the discovery by Kodi Mosier, a 10-year-old student at Ticonderoga Elementary School, the company, the Bureau for At-Risk Youth, based in Plainview, N.Y., recalled the pencils. … A new batch of pencils will have the message written in the opposite direction, so when they are sharpened, they will read "Too Cool To Do" and finally "Too Cool."