Middle age is amazing. Being tired is amazing. Not caring is amazing. Bear with me for a few minutes as I explain because I’m certainly not talking about the constant new aches and pains my body insists on discovering. Most days, I can’t tell if I’ve injured myself or if this is just how I am now. I’m talking about the level of I don’t give a rat’s ass only crossing the threshold into middle age can give you. I published my first book eight years ago, and in the time since, I’ve published three more. My sales aren’t great—not because the books aren’t good; my reviews are positive—but because…