I'm counting on my fingers here, but I'm definitely within a year or two of the age when my father asserted it was impossible to sleep all night. Bed at 11 or 12 and awake at 5 am, I think he said, complaining there was nothing to do at that hour-- which in those netless days of the mid-late 70s there wasn't. I'm waiting for this old-age insomnia to hit me. Two early days of up for 7:30 has me in a zombie state. I want only to collapse into bed and sleep until 10 or 11 tomorrow, and probably will, which is why I must make up the guest bed tonight. But I'm too tired even for that.