xkcd.WTF!?

Explanation ➲

The narrator discovered that it is simple and inexpensive to have a commemorative plaque made, and so had a commemorative plaque made to record that event. The comic both indicates the lack of knowledge many people have about how simple or difficult it is to do a certain thing, and the over-the-top response a person might have to a relatively mundane discovery.

The comic was published on May 5, the holiday of Cinco de Mayo, Europe Day and Dutch Liberation Day, and the day before the Coronation of Charles III and Camilla. The comic subverts an expectation that a plaque about May 5 would be to commemorate either one of the many world events that previously took place on a May 5 in various years, or more specifically the 1862 Battle of Puebla or the 1964 founding of the Council of Europe or the 1945 Liberation of the Netherlands, which all took place on May 5 and inspired the respective holidays.

The title text describes a second plaque mounted below the first one, boasting that a week later they learned out how to use a masonry bit, presumably to mount the first plaque onto a stone wall.

The earlier comic 699: Trimester also features a similar situation in which a seemingly official and authoritative item can in fact simply be purchased by a layperson.