I found the part when he said he was not surprised that he was failing art class interesting--not surprised because he knows he's a failure, knows this because his voices tell him this.

The rhythm, the constant beat, of his negative voices seem to have rendered him unable to think rationally, to ask for proof of his assumed--all encompassing--failure, or to ever act in a positive way, and then to one day disprove his assumed--all encompassing--failure.

And the latter causes a self-fulfilling prophesy, which builds up more proof of his failure, and thus gets stronger and stronger.