He flit hither and yon tither and wither and never stays still. What he said yesterday he refutes today and then reconsiders and resays it again. If you CAN keep up with him then you are in excellent shape. Also a moving target is less apt to get hit. There is that.
On a scale of 1-10 in terms of YOUR mental agility what number are you? Of course da big cheese is 100. He always tentuples any scale.