Yeh, that one's a grim one. Agree about sharp edge too- the rock on Blencathra is greasy at the best of times and I wouldn't fancy doing it in the wet. Had a go at Jack's Rake on Pavey Ark a couple of years back on a wet day and had to turn back- it was like being on ice.
Yeh, earworm's a good expression and sums it up nicely. My worst (and sadly most frequent) one is 'Robin Hood, Robin Hood, riding through the glen..' (made all the worst by the fact that I only know the first verse).