Android Lollipop annoys me (a little bit)

There's a way of thinking that worries me: a “new operating system” must look graphically different from the previous version of the same operating system. Premise: I have been upgraded to Android (so-called) Lollipop. (Second premise: I own a Samsung Galaxy S4 — something I regret, but it's too late and I'll keep it till I die or till it breaks — whatever happens first).