Wishing makes it so

Another snippet of correspondence from the files of the Royal Mythological Society:

Dear Doctor Clattercut and Professor Bromfield

As it is the season for falling stars, and this summer we may expect a number of green meteors from the tail of Comet Meadowvane, I wonder what will result from the consequent spate of wishes all coming true?

Yours,

Frank Dyson,

Greenwich

Dr Clattercut replies: It has been my experience that, for every person harbouring a given wish, there is somebody else who wishes the exact opposite. Therefore, although hundreds of wishes will be granted during this year’s meteor showers, the overall effects can be expected to cancel out. You’re very quiet, Bromfield.

Prof Bromfield: I just realized that I’ve blown rather a lot of money at the bookies.