Discworld should be mandatory reading

I think the only Discworld book I haven't read is the cookbook. Everything else in the series I've read at probably at least three times. I think the core series should be mandatory reading in high school, and the Tiffany Aching books mandatory for all girls age 9 and older.

The buried lessons on ethics, civics and critical thinking are stunning. I think only Raising Steam went askew, partly because it was trying to tie up an entire epic saga of loose threads.