Depression
Depression is an interference phenomenon Meadows Foundation Chair and Associate Professor in the School of Behavioral and Brain Sciences at The University of Texas at Dallas told the Huffington Post.
This interrupts the person’s ability to think. “We hypothesize that when individuals with depressed mood are exposed to stimuli, such as a meaningful song or a place that evokes sad feelings, the brain fixates on that and can't focus on daily tasks such as a phone conversation or completing a grocery list."