Canst thou not minister to a mind diseased
Pluck from the memory a rooted sorrow
Raze out the written troubles of the brain
And with some sweet oblivious antidote
Cleanse the stuff'd bosom of that perilous stuff
Which weighs upon the heart?
-Macbeth Act 5, Scene 3
As the royal physician had told Macbeth, "Therein the patient must minister to himself." Bob was willing to admit that he was mad, though he didn't bother to do much about it. His madness caused him to feel his emotions in extremes, or perhaps it was his extreme emotions which made him mad. He knew his vengeful, violent thoughts against a clown and a little boy were not those of a sane man, but what could he do? The prison psychiatrist was a quack, and the closest thing to medication in prison was moonshine.
Admittedly, sometimes the badly made alcohol did help to dull Bob's senses and his miseries...in addition to sometimes leaving Bob temporarily blind. It helped when Bob was overwhelmed by his frustrated desires for vengeance, and his grief and self-loathing at many of the poor choices he had made. Sometimes, Bob was incredulous that he hadn't taken to sleepwalking, like Lady Macbeth, though he hadn't yet gotten actual blood on his hands.
Sometimes Bob wished that he couldn't feel anything; perhaps that would have made his life easier.