Never let the fluff of a class define the personality of a character. Let Clerics be Atheist, let Barbarians be cowardly or calm, let Druids hate nature, and let Wizards know nothing about the arcane
Fun Fact: A monk in armor loses Martial Arts, Unarmored Defense, and Unarmored Movement, but keep all of their other abilities, including subclass features, and Stunning Strike works with melee weapon attacks. Make a Monk in Fullplate with a Greatsword >=D