It’s really hard being a historical writer. We work for hours, sometimes years, learning as much as we can about the period we are writing in – from speech, to food, to dress, to religion, and on and on. Even then, there is always someone who knows more than you and things trip you up. When they are pointed out you cringe and make a vow to not do THAT again.
One of the easier things to get, however, are the social mores and constraints. These, in my opinion, are biggies . .