My feeling after seeing these brief excerpts is that he was an “impostor”. That is, he was not a “smartkid”, but knew how to act like one, for example with his cute remark that his dream was to own a slurpee machine. He goes wrong with his ambition to “make scientific discoveries”, though. This is supposed to be cute also, but the act has already worn thin in the few seconds we see of this presentation. We need not doubt that he could act his way to good grades with the kind of soft topic that we see here, but I think he went off the rails when it all fell apart for him at the graduate level.
The Joker persona was a very obvious recourse in his case: “I’ll show you who’s smart.” - very much like Syndrome in The Incredibles, as well. He wouldn’t have had nearly the draw of Heath Ledger’s Joker, of course, and my feeling is that that portrayal was a major influence on him.
Yes, similar to the guy that slaughtered 6 at a school in Oakland in April.
Hey, why weren’t flags flow at half mast for that?