to (one's) bones

1. Very much; to an extreme degree. I can't believe you pushed me into the pool! Now I have to walk home soaked to my bones! We felt shocked to our bones to read about the things our neighbor had done.

2. Through and through; thoroughly; in every manner or respect. Even since she was a kid, Mary has always been to her bones a natural-born leader. Though he grew up in America, Henry is still a Brit to his bones.

to your bones (or to the bone)

in a very fundamental way (used to emphasize that a person possesses a specified quality as an essential or innate aspect of their personality).

2003 Eve Gloria is known today to be a conservative to her bones—a true monarchist.