I know how you feel, I've read the whole manual twice (almost) in its entirety,i also started rigging,i have forgotten most of the stuff i learned earlier,since i haven't rigged anything for about 9months
(and try to keep my knowledge (partially) updated regularly)
but stuff you don't actually use on a more or less daily basis, tends to slip away quite easily,
leaving only a faint extremely frustrating trace of "I know, I know this...".
I tend to blame it on my age (42).







