OK, I have to check this out myself. I find there are areas of the fretboard I know cold, but others I have to interpolate using octave patterns. That's even before working with the guitar fretboard workbook.

It may be silly, but I also find I have to think too long sometimes going through the alphabet backwards. On the spot, I'll think 2 frets below an G is an A, not an F. Just not really used to thinking of the alphabet backwards. That's improving though :-).

I can pretty consitently get a perfect score on the fretboard trainer in about 1:20, so I'm getting there!!