I think you hit it right on the head.
Lots of animals are curious, it is hard wired into them, a means of getting them to learn more about their surroundings. With us, we develop an addiction to it, it is pleasurable on a sensual level. It's just the sort of emotion you would expect for evolution to favor in a creature whose major equipment for dealing with reality is an overdeveloped brain.
Nice picture, but I quit smoking four years ago.