Making money one one's own stupidity

Read this blurb from Market Watch.  The point is, too many bullish traders indicate a downturn. Now I have learned to bet against myself, since I am mostly wrong. So there must be some sort of uncertainty bias in us, something that tells us "Beware when you are so certain".

This old bull market is finally finding a little love as the S&P 500 SPX +0.30%  pushes yet again into record turf. Will it be its undoing?
The American Association of Individual Investors on Thursday said  46.11% of retail investors described themselves as bullish in their latest weekly survey, up from 39.81% the previous week and the highest reading since Dec. 26. The survey found 23.65% described themselves as bearish, down from 26.96% the previous week, marking the lowest reading since late June. Some 30.24% were “neutral,” down from 33.23% a week earlier.
The survey tends to serve as a contrarian indicator, so this is the sort of new high that might actually start to prompt some concern for market bulls. “While less than half of individual investors are bullish, we are getting close to that 50% threshold that has spelled short-term trouble in the past,” wrote analysts at Bespoke Investment Group, in a blog post.
–William Watts