The Importance of Strategic Understanding in Hikaru

I was actually thinking A4, but it's very hard to move to make. Cause it's Sax upon. You can't take it immediately because D takes E4, Rook A4 and QD2 - typical idea. But for example, why can play ED5 and then take the pawn? Or why can move the rook to Fenn D2 and then try andtake the pawn? And take A4 after B4. I really like this move B4. He took very natural B7, he runs Rook B6. Basically, my idea was if bishop C7, I'm in time to play A4. My knight on B6 is a funny outpost