To “wear your heart on your sleeve” means to show your feelings to the world. It describes a person who hides nothing, and that emotional honesty makes them vulnerable. Stan Larkin didn’t wear his heart on his sleeve. He literally wore his heart on his back.
We see with our eyes and hear with our ears. At least that’s the conventional way to do things, but no one is calling Neil Harbisson conventional. Neil is colorblind. Unlike many colorblind people, who are unable to see just a few specific colors, like red or blue, Neil can’t see any colors except for grey. He has spent his whole life experiencing the world as only different shades of grey. That is until recently.