This book is a collection of stories and jokes about incidents when people do something silly or embarrassing because of a loss of memory.
Such failures of memory are sometimes known as a "senior moment" because they are often associated with older citizens, though in fact embarrassing memory failures can occur to people of any age. (One of the "senior moments" in this book happened to Abraham Lincoln when he was only 23, and another to Max Plank when he was 34.) As the book itself says "senior-momentitis is not a condition restricted to those of advanced years."
A large minority of the stories in the book refer to actual or alleged events involving real people, but most are clearly jokes or urban legends.
This book could easily have been in very bad taste - e.g. making fun of old people in a cruel way - but most of the mockery is gentle rather than cruel.
Example of a story from the book: an elderly lady was stopped in a shopping centre by a young man with a clipboard who explained that he was part of a research project.
"Have you ever had a senior moment?" he asked. The lady looked thoughtful for a few moments, and then asked "Sorry, what was the question again?"
"We'll put you down for a 'Yes'" replied the researcher.
Reasonably entertaining if you like this style of humour. There are several similar books from the same publishers by this author, Geoff Tibballs, or by Shelley Klein, which include:
The Book of Senior MomentsMore Senior Moments (The Ones We Forgot)The Book of Senior Jokes: The Ones You Can Remember