The alcohol from the beer he's been drinking.
The need to read.
He took to many painkiller pills
HIS POWER LEVEL WAS OVER 9000!!!!!!!! (so he was thinking on a new plane of existence)
He and his wife were getting separated because of Clarisse's influence.
The winter islands are represented by their cold beds.
The sea represents how they are growing separate.
Ray Bradbury likes winter wonderlands. :D
The government has brainwashed him.
Clarisse planted a seed of doubt in his mind.
He doesn't remember because he's drunk.
He started watching Curious George! :D
He's bored of all the TV programs.
The walls are influencing him.
He think she's really empty in comparison to Clarisse and himself.
He thinks she's an Inferi (yes divyya, HP reference!)
He thinks that she's too shallow and doesn't think things through.
He feels like being a bully.
She feels like being a bully.
They're both bullies.
Clarisse is trying to make them break up.
He's frustrated that Clarisse is dead.
He thinks that maybe Mildred may be able to comfort him.
He wants to prepare her for one of his famous punchlines.
He doesn't like broccoli.
Because Montag tried so hard to save the old woman.
Because Montag said "Once upon a time..."
Because its written all over his face (literally).
Because Montag confided in Beatty the truth.
Depends on how sick he is.
Because almost every book had a contradiction to one of the many societies out there, such as the Unitarians, the second generation Chinese, etc.
Because the government were afraid that its enemies would spread propaganda using books.
Because the government wanted to rewrite history in its own way, and any existing books might contradict them.
Because the government thought that books were a weakness to national security.