You didn't answer the question. Who were you before you were TimMykes? I mean, you claim it was the dumbest post on ET for years, but you joined less than a month ago. Were you just a visitor for years, with no login ID?
Because if you have been visiting this site for years, you would know the journal section. So I didn't think there was a need to answer what would be obvious to you, as a years-long visitor/member of this site.
Since the changes are often gradual. A human will not observe the changes, especially when not looking at the long-term data through objective means (data analysis). A man slowly gaining weight won't notice it until being weighted, shown a picture of himself or finding that his old clothes do not fit.
I think it depends on the nature of the edge. When it comes to inter market correlations and market structure exploitation I’ve seen some guys get clipped pretty hard before it became obvious that what was once an ATM no longer was.
Longer one trades, excuse of market not acting right vanishes when you have lived through some form of it several times. I have over 100k hours of screen time, I have tested some methods over 50 years, I am very good at chart reading for my own self, nothing is new any more. People don't take enough time to learn, they open an account and like the new account is yelling "come to me" and most before long say the game is rigged, of course it is rigged, first bright thing they discovered. People lack ability to adapt, instead of figuring how to trade, figure out what to do when the position is wrong. Figure out what to the left of now the trade should not been taken. What am I thinking...We need more fresh meat.