This is how you really know you are mortal:
1. You wake up to find a patch of stinging rough skin on your right eyelid, a phenomenon you have never experienced before and which gives you a clear idea of how at least one eye will look if you make it to 80.
2. You have to look up the spelling of "apropos," a word you could spell in your 30s with your hands tied behind your back and in a drunken stupor.
3. You discover you enjoy something like Sudoku.
4. Your friends discover they enjoy knitting.
5. You discover you can enjoy something like Sudoku only when you work with a pencil.
6. You schedule more doctor's appointments in a single month than you have in the previous decade of your life, appointments where the doctors sigh and shake their heads and prescribe either Vitamin E, back-strengthening exercises or stool softeners.