No, it’s not what you think. At the beginning of the Industrial Revolution, before alarm clocks were invented, people hired a “Knocker-up” or “Knocker-upper” to tap or shoot peas at their windows at an appointed time until the person was awakened. This occupation existed in England and Ireland until well into the 1920’s. It required a high degree of punctuality, and provided employment to the unskilled common man or woman. Like so many occupations, it eventually became obsolete, and forgotten. If your ancestor’s trade is listed as a “Knocker-upper” on the census or other genealogical record, now you will understand what that means!