For instance, I was formerly taught when abbreviating the names of the united states, you use the postal codes (ex: Connecticut = CT). However, the AP Style's rules for state abbreviation is all over the map. AP Style has its own unique abbreviations for the states (ex: Connecticut = Conn.), except for: Alaska, Hawaii, Idaho, Iowa, Maine, Ohio, Texas, and Utah which are never abbreviated. Memorizing which states are not abbreviating, let alone the individual abbreviations is extremely difficult.
I appreciate the AP Stylebook for being extensive and in-depth, yet since the style itself is so specific and unrelentingly unyielding, I find myself glued to book whenever writing or editing a story. Looking up every other word or phrase can make for a bothersome and slow process of publishing.