Well he was either frightened or suddenly overcome with the urge to quote Psalm 22:1. Or, as I prefer to think, the authors of the gospels of Matthew and Mark (but not Luke and John) felt it was important to show Jesus' particularly Jewish roots at that moment, as well as his identification with King David, as well as, of course, the more human side of Jesus.
There being no *human* side to Michael makes it difficult to match him with the human Jesus.
I expected I might get a rationalization like this except that this rationalization does not hold water.
To suggest that Michael who spent thousands and thousands of years in Heavenly Bliss knowing full well what that entailed and that Heavenly experience firmly and deeply imprinted on him for thousands and thousands of years , that he would after only 30+ years as a human forget? Proposterous, absolutely proposterous. It reaches just much too far.
There are JWs now who wait on baited breath every day because they can't wait for God to come and destroy the Earth just so they can live in paradise because they believe it will be paradise because WT has convinced them of that so well. In all the WT publications you see JWs smiling gleefully as the world is being obliterted around them. Yet all Jesus had was faith and he was frightened, Why, the obvious answer is because he did not have the thousands of years in a previous life and experiences as Michael to alleviate those fears.
Using the logic of him quoting Psalm 22:1 is flawed as he did not quote the full Psalm. If his intent was to quote the Psalm he would have quoted the next two phrases...he didn't. Jesus' remark was clearly born out of fear or a last moment of weakening in his faith. A weakening in faith which would not likely have occured with 5000+ years under his belt of being a Heavenly Angel.