Trust me, laziness is a real thing; even when everything in the world points towards doing the work being the best thing for you, you just can't be bothered.
Of course it's a real thing. He never said it wasn't. What he said was that it doesn't explain anything, and that's true.
Laziness is a symptom, not a cause. It's like diagnosing someone with a "cough". It may be correct, but it's pointless, because it's obvious and tells you absolutely nothing about what to do.
At what point is a personality merely a symptom? If everything about us is a result of our ailments, and all of our ailments have treatments, how does a person know which parts of his personality are him and which aren't? What am "I" then?
I would probably say that we can classify our personality as the difference in sets of what anyone with our ability and in the same situation would do, and what we do.
That being said, our ailments could probably be categorized by affecting all aspects of our life equally and in full measure of time (i.e something that doesn't fluctuate across the years is probably an untreated ailment).
You're the little sane bit sitting on top herding the various cats of brain lobes, psychological disorders and just plain basic insanity into acting as a useful whole every day.
A sufficiently self-managing nutter is indistinguishable from a genius.
