knowing

Have you ever solved a 4x4x4 up to the PLL stage, glanced at the front face and a portion of the right face, and had this instantaneous feeling of extreme unfamiliarity with the color pattern you saw there? Has this led you to know that you have parity, before you can even check? Have you...

When do you guys think you "know" a method? E.g. I think that I know a method when I can sub-30 average it. But I know of somebody who thinks you should be sub-15 before you "know" it.