Never a dull moment—or so we are led to believe—if we pause long enough to consider the sheer amount of thoughts that race through our minds at any given moment. For some of us, it can seem to be a never-ending and outright overwhelming process. If this defines the way your mind works, I have good news: you’re normal. In fact, for most of us, the issue is not so much the number of thoughts racing through our mind, it’s the content.

Researchers have determined the number of thoughts an ave...