I am repeatedly amazed by how fast the body can recover so many healthy processes, and also heal, when someone quits smoking (I'll send you a link for that timeline---it's remarkable!). And, naturally, the younger you are when you quit, the better your chances of healing faster and more completely.

Our skin and bones literally, completely, replace themselves on a certain schedule, and with surprising regularity. Of course, it slows down as we age. But it is astonishing, so amazing.

And I love the immune system. It's not perfect, but it's pretty cool.