People often assume that nighttime dreams are much stranger than the thoughts that drift through our minds during the day. A new study published in Consciousness and Cognition shows that waking mind wandering is just as densely packed with bizarre elements as dreaming, though the nature of the weirdness differs. The findings suggest that both states share a similar foundation of spontaneous offline simulation, challenging old ideas about the strict boundaries between sleep and waking consciousness. Spontaneous thoughts make up a large portion of our inner mental lives. When our attention drifts away from the task at hand, our minds wander freely through memories, fantasies, and hypothetical scenarios. Nighttime dreaming operates in a largely similar way, unfolding without our direct, deliberate control. Psychologists and neuroscientists have long debated whether dreaming and waking mind wandering exist on a fluid spectrum or represent entirely different categories of experience. A central point of debate has been the concept of bizarreness. Dream bizarreness refers to the unusual, unlikely, or physically impossible events that happen while we sleep. Common examples …