That's a great point.
I almost think that the offense of the Giants is SO complicated... lots of audibles, reads, etc... that nobody can really understand it until they're in year two anyway, and it probably takes 4+ years to master.
I read an interview with Bart Starr a bunch of years ago where he was talking about working with Vince Lombardi, and at one point Lombardi is saying to him, "what's wrong with you? You don't SEE! Why can't you see? Then one day he got under center... and everything made sense to him all of a sudden. He could "see." And from that point on, he was a different player, a different quarterback.
I think that light may have gone on with our boy Eli.