"You can't mean me!?" (3)
I believe the answer is:
moi
'you can't mean me?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for moi that I've seen before include "Just me, monsieur" , "Daniel arap . . ., Kenyan president for 24 years" , "affected me" , "Me - in France" , "it's the writer being facetious" .)