Dyed in the Wool

The expression "dyed in the wool" comes from the practice of dying wool before it is spun into threads, so the color is least likely to fade or change.  Idiomatically, the term means established in one's beliefs or habits; a state of steadfastness, especially with respect to one's political, religious or social beliefs.

Rumi says, "When you let go of who you are, you become who you might be."