For any of you who are really familiar with my stuff, this isn't a concept (In the Building Blocks/Principles/Concepts mode) but rather a meta-concept. The looking glass. So far, I think I've only really written about concepts in the Training Journal and in some class handouts. "Concepts" is my catch-all phrase for the way understanding changes. At one point in my martial career, I wouldn't have understood that a 'fight' and an 'assault' were different and largely unrelated things. Now the concept seems so obvious that I have to work at remembering that some of my students may not understand a difference exists.
The meta-concept is the "Looking Glass." A reference to Lewis Carroll's book. You cross a threshold of experience and things that made sense in a certain way now make sense in a different way. When you were eight years old, girls were icky and there were girl germs and love was stupid. And love songs were stupid and poetry about love was stupid... right up until you fell in love for the first time. You stepped through the looking glass and even though an eight-year-old could tell you were being stupid it didn't matter. Because the logic and reality of one side of the looking glass no longer applies.
Falling in love. Having a child. The death of a parent. The death of a close friend. Your first fight. Your fiftieth fight. All are thresholds, and once you cross the threshold the way you think and the way you see the world changes on a fundamental level.
"Let it go." "Forgive." "Just get over it." From one side of the looking glass, this is worthless, meaningless advice. But everyone who has crossed that particular threshold has, at some point, decided to let go. From the other side of the looking glass, it is simply obvious.
"Put him down." "He never gets a move." "I own every beat in the rhythm." These are simple tautologies on one side of the looking glass, near-impossibilities on the other.
One of my friends has a metaphor for power generation. "Spill the tea." I'm close enough to the threshold to see it, but nowhere near close enough to use it.
When someone gives you advice from the other side of the looking glass, just because you don't get it doesn't mean it's not true. Conversely, when you cross a threshold, it doesn't make your new truth truer than the earlier truth. Just different.