What I am sick of in books.
Today, that is. I expect to be sick of something else tomorrow. :-)
18th and 19th century heroines who are wealthy, educated, daring, and plot-conveniently innocent.
Heroine with money and position, who got into plenty of "young ladies shouldn't behave like that" trouble in her past. Now twenty-something, and has daringly finagled her way onto a ship. Has been exchanging mysterious notes with someone off-ship in the current port in pursuit of her many twisty subplots.
And when it's revealed that the hero's interesting scar is because he was shot at some point in his past, she's all shocked. It apparently never occurred to her that in the adventuresome life he's occasionally talked about, he might have been at the wrong end of a gun once or twice. Because yeah, that never happens to someone in battle.