GU in a comment there reminded me of the Chofez Chaim (al haTorah in P’ Bechukosau) who asks what it means when we say “anu ameilim” and get schar but “heim ameilim” and don’t get schar. Doesn’t the tailor get paid for the suit he makes? The Chofetz Chaim answers that if the tailor works hard but doesn’t complete the product – his work is ameilus, withouth results – he doesn’t get paid. The chiddush of learning is that even if it is ameilus, even if you work 10 hours to figure out pshat in a Tosfos but still don’t get it, you still get schar for the effort.
Perhaps this is (derech derush) the meaning of Bilam’s words, “…v’lo ra’ah amal b’yisrael.” Ameilus is a wonderful thing – why would Bilam say as a bracha that Hashem’s doesn’t see our ameilus (see Ohr haChaim, and this is why Rashi and Ramban reinterpret the word)?
The answer is that Hashem doesn’t look at us like he looks at the tailor who can’t finish making the suit or a student who hands in an incomplete paper for a course, the definition of “ameil” according to the Kol Bo. Hashem doesn’t look at our efforts as work that is incomplete or without results, even though no matter how much we learn or how much effort we put in we will always fall short of doing justice to the vastness of Torah. In G-d’s eyes, it is as if we accomplished exactly what he expects and wants of us.