[SamvitJ]

Could there be a confirmation bias to this observation?

You distinctly remember the times you had an outlier belief which you ignored to your detriment, but tend to forget all the foolish-seeming ideas you had which were indeed very much foolish when taking stock of the past.

I think the opposite advice might be even more useful for many, many people: be more scared of overconfidence, because you know less than you think. Research on cognitive biases and the underperformance of "experts" in many fields tends to support this view.

[cainxinth]

Plus hindsight bias and survivorship bias