Remember the game
Hot Lava that you used to play as a child? Walking only on furniture, scraps of paper, anything, to avoid walking on the floor because it was hot lava? Well, I swear cats play this game too, based on observing Simon. (Can other cat owners verify this?) Simon does walk on the floor, of course, but if at all possible, he will jump on any piece of furniture if it's even remotely along the way of where he is going, even if it is a longer rout.
(I can't believe that there is a Wikipedia entry on "Hot Lava"!)