Humour: The Know It All by AJ Jacobs

Heinemann £10.99 pp352

This much I know: that to write a successful funny book is difficult; that it helps if the idea behind it can be summarised in a simple, snappy sentence; that it should not be too long; that the author should be good company for the reader; that it doesn’t hurt if he works for a high-profile magazine whose contributors and stars can provide complimentary quotes; that, even with all these things in place, the result can still be unamusing.

The Know-It-All, a comic exploration of the importance of knowledge, does well by these criteria. Its concept, which has the author setting out to improve himself by reading all 33,000 pages, 65,000 entries and 44m words of the Encyclopedia Britannica in a year,