One of the nice things about being really rich, I have sometimes mused, must be that people laugh at your joke, however half-baked the gag.

For we all unashamedly chortle at the wit of the super-rich whose custom we seek. Frankly, it is very difficult as a front-line private banker not to be just a touch obsequious when cultivating the really wealthy client.

Personally, my own mundane jokes are quite awful, as regular readers will know, e.g. Why do the French ha...