The phrase "short, sharp shock" means "a punishment that is ... severe but only lasts for a short time". It is an example of alliteration. Although the phrase originated earlier, it was popularised in Gilbert and Sullivan's 1885 comic opera The Mikado, where it appears in the song near the end of Act I, "I Am So Proud". It has since been used in popular songs, song titles, and literature, as well as in general speech.