Here is a word from “The Mystery of the Taxi-Cab” found in The Complete Casebook of Herlock Sholmes. I have read this word before, but never looked it up to be certain what was meant by it.

Aberrations – a departure from what is normal, usual, or expected, typically one that is unwelcome

Usage: “Accustomed as I was to the remarkable mental aberrations of my amazing friend, I could not help wondering at the methods he employed in this mysterious case.”