There aren't enough small numbers to meet the many demands made of them.
References
Gardner, M. ``Patterns in Primes are a Clue to the Strong Law of Small Numbers.'' Sci. Amer. 243, 18-28, Dec. 1980.
Guy, R. K. ``The Strong Law of Small Numbers.'' Amer. Math. Monthly 95, 697-712, 1988.