Over the years (48), I've done a number of different training programs (so to speak, some are admittedly pretty half assed).
The two things that really qualify for me as "paradigm shifts" (if you'll excuse the business buzzword):
1 New conception of volume. 5 sets of 15 pushups with no real rest in between??? Usually in the past it was pretty much 3 sets or 4. And reps would usually max out at 12. And the rest would be 1-2 minutes. Woof.
2 New conception of pace of progress: I used to push for some measurable progress every week. And of course that is why I would try so many different training programs, because after a few months of that, you're either injured, overtrained or frustrated with the plateau.
Now, I'm fine with the fact that I'm at a certain step for a few weeks. It's a totally different perspective.
Thanks very much Coach and company!