A FRIEND of mine has a bad habit of narrating his experiences as they are taking place. I tease him for being a bystander in his own life. To be fair, we all fail to experience life to the fullest. Typically, our minds are too occupied with thoughts to allow complete immersion even in what is right in front of us.

Sometimes, this is O.K. I am happy not to remember passing a long stretch of my daily commute because my mind has wandered and my morning drive can be done on autopilot. But I do not want to disappear from too much of life. Too often we eat meals without tasting them, look at something beautiful without seeing it. An entire exchange with my daughter (please forgive me) can take place without my being there at all.

Recently, I discovered how much we overlook, not just about the world, but also about the full potential of our inner life, when our mind is cluttered. In a study published in this month’s Psychological Science, the graduate student Shira Baror and I demonstrate that the capacity for original and creative thinking is markedly stymied by stray thoughts, obsessive ruminations and other forms of “mental load.” Many psychologists assume that the mind, left to its own devices, is inclined to follow a well-worn path of familiar associations. But our findings suggest that innovative thinking, not routine ideation, is our default cognitive mode when our minds are clear.

In a series of experiments, we gave participants a free-association task while simultaneously taxing their mental capacity to different degrees. In one experiment, for example, we asked half the participants to keep in mind a string of seven digits, and the other half to remember just two digits. While the participants maintained these strings in working memory, they were given a word (e.g., shoe) and asked to respond as quickly as possible with the first word that came to mind (e.g., sock).