How many of you complete a program or cycle without ever messing with the program? Are any of you never derailed by diet, sleep, or stress issues?

Being in my 30's, I have found that lack of sleep and stress forces me to do things like drop assistance work out of the equation once in awhile - perhaps more than I would have had to when I was younger.

I've also missed a workout or two, here and there, and ended up doing two days a week instead of three.

Has anybody ever experimented with myo-reps in their program a la Borge Fagerli, or the Autoregulation / RPE methods of Mike Tuchscherer? (I believe RPE stands for Rates of Perceived Exertion)