Jason -- No doubt there is a lot to be learned from logging the rationale motivating a trade and reviewing it later. If you will indulge me, I am suspicious of choice data. It would seem your description of the choice would have to include "GDP, corporate earnings, discounted cash flow analysis, technological trends, demographic shifts, ..." relative to what is in the market already. If you expect earnings to be up in a quarter, buy and then discover everyone else had the same expectation such that the stock declines, is that due to skill or luck? The decline may be totally unrelated to earnings and instead an effective tax rate change, R&D miss, market share decline. My point is there are a ton of variables that affect price and, it would seem, ample room to attribute performance to the wrong reason.