mind-your-own-business

And not just sick in the body but in your mind, because you start obsessing.
How Taryn Toomey’s ‘The Class’ Became New York’s Latest Fitness Craze|Lizzie Crocker|January 9, 2015|DAILY BEAST
The questions going through my mind are: How on earth are there Kalashnikovs and rocket launchers in the heart of Paris?
Ayaan Hirsi Ali: Our Duty Is to Keep Charlie Hebdo Alive|Ayaan Hirsi Ali|January 8, 2015|DAILY BEAST
True, this may not be what James Madison had in mind when he was writing the Bill of Rights.
Why We Stand With Charlie Hebdo—And You Should Too|John Avlon|January 8, 2015|DAILY BEAST
I was a little mystified at how benignly he responded to my questions about his business activities.
I Tried to Warn You About Sleazy Billionaire Jeffrey Epstein in 2003|Vicky Ward|January 7, 2015|DAILY BEAST

This reporter knocked at the Wilkins home on Tuesday morning but received neither an answer nor the business end of a shotgun.
The 7-Year-Old Plane Crash Survivor’s Brutal Journey Through the Woods|James Higdon|January 7, 2015|DAILY BEAST
He remembered something—the cherished pose of being a man plunged fathoms-deep in business.
St. Martin's Summer|Rafael Sabatini
Other things being equal, the volume of voice used measures the value that the mind puts upon the thought.
Expressive Voice Culture|Jessie Eldridge Southwick
He was too drowsy to hold the thought more than a moment in his mind, much less to reflect upon it.
The Wave|Algernon Blackwood
"There's just one thing I'd like to ask, if you don't mind," said Cynthia, coming suddenly out of a brown study.
The Boarded-Up House|Augusta Huiell Seaman
The vision—it had been an instantaneous flash after all and nothing more—had left his mind completely for the time.
The Wave|Algernon Blackwood

British Dictionary definitions for mind-your-own-business

noun

a Mediterranean urticaceous plant, Helxine soleirolii, with small dense leaves: used for cover

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012