I easily "forget" how to do it as well and it comes in many forms:
a) "Away from the game": Was away on vacation for a month this summer. It took me several intense weeks - (not just hours, Yel ... lol) - to get the hang of it again ...
b) "Ghostbusting": Sometimes I get (too) caught up in doing TT´s and SL´s. When entering the MP-arena, I´m usually like a frog on ice - and getting really anoyed ´cause everybody is evil to me ...
c) "Speeding up": At a certain time I spent quite some time at slower speed-classes to see how well I managed. When I went "back" to Phantom: - nothing felt natural ...