Bored
His mind would not stop buzzing with incoherent and pointless thoughts. There was nothing to ground him, nothing to focus on; so his brain went into overdrive and it was driving him insane.
He calculated the number of books the uppermost shelf could hold then multiplied that number by the number of shelves, squared it to factor in the amount of cases in the room, and compounded it with the number of books scattered across the floor. Simultaneously, he was dissecting each and decomposing it down to its atoms, figuring what elements made up each component (ink, paper, leather) and how many electrons per neutrons each would have.
Than of courses, there were the smells floating in from the open window behind him. With each new breeze, came a new fragrance. His mind automatically focused on the scents, deciphered their properties, calculated their approximate distance from his person, located their origin, separated their molecules and came up with no less than seven other outcomes of mixing those particular elements in a different manner.
With each new wind, dust would fill the air from the surfaces of the flat around him. Factoring in the number of breezes that caused such a storm and the amount of dust in the flat, he calculated how many particles of dust he breathed in; first by the second, than by the minute, then hour, until he found the amount one would breathe in should they live to be millenniums old.
And that was only including the thought process that had a reason or line behind them. There were so many others that were just little tidbits, ideas from old cases, deductions from nonexistent specks, references to miniscule details; IT WAS DRIVING HIM INSANE!
And John thought he just enjoyed being dramatic. He needed something, anything, to stop this information overload. All of it useless, all of it pointless. He needed a case!