You will know when you've got it (9)
'you will' is the definition.
The answer and definition can be both related to thinking as well as being singular nouns.
Perhaps there's a link between them I don't understand?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for erudition that I've seen before include "Knowledge, learning" , "State of learning or culture" , "Great knowledge" , "Great learning" , "being widely read" .)
But I've got no explanation for this one! Could you help me understand?
(Other definitions for learning that I've seen before include "information" , "Lore" , "Large inn (anag)" , "Researching - scholarship" , "The gaining of knowledge" .)