I constantly read Facebook statuses saying things like: "Omg can't sleep brain please turn off already!!"
Except it's usually 'oh em gee' and 'turn of' but I'll look past that.
The thing is, these statuses come from people who until they informed me via this status, had led me to believe they didn't actually have functioning cerebrals.
So maybe, just maybe (And I'm just throwing ideas around here like a whore on brand new Egyptian cotton sheets) it's not that your brain can't turn off, but perhaps it simply decided to turn on ... At an inconvenient moment.
Maybe you could try to 'turn it on' at a more appropriate time? (Complete with full-bodied enthusiasm of sexy pole dances and any amount of icecream to the body because let's face it, you need a decent wedge of help.)
An appropriate time like... Using the self service machine at Coles. Or touching off your Myki during peak hour. Or even the good ol' simple Hook Turn that separates the Einsteins from the 'Tards in Melbourne's CBD every day between 7 - 9 and 4 - 6.
But if it so happens that your brain never gets the chance to experience exhaustion after a long 17hr day at being useful, maybe try and put your time to better use.
Abraham Lincoln, Bill Clinton and Vincent Van Gogh - all insomniacs.