A normal distribution of returns with repeated play will still lead us to expect at least one investor with Buffet's track record (if my econ. prof's math is to believed----I haven't have cause to look closely).

Buffett claimed at some point that they calculated he was a 3 sigma event, then a 4 sigma, then a 5 sigma, then stopped calculating because it was getting embarrassing.

Here is his contemporary, fuller argument.