It's easy to think of trivial examples of one-time victories - for example, an early Bitcoin investor realizing that crypto-currency had potential and buying some when it was still worth fractions of a cent.

Actually, I've been working on a mini-essay on exactly this topic: because of my PredictionBook use, I have a long paper trail of explicit predictions on Bitcoin which implied major +EV at every time period, but I failed to meaningfully exploit my beliefs and so my gains have been far smaller than they could have been.