Our minds naturally wander for much of our daily lives. Here we review how mind wandering, or task-unrelated thought, impacts comprehension during lectures and reading, and how it relates to general academic success. In some situations, mind wandering may not hinder performance, and may even aid in creativity, future planning, problem solving, and relief from boredom. We distill research on the negative and potentially positive effects of mind wandering to suggest ways that teachers can reduce and redirect mind wandering in the classroom. To conclude we suggest that, rather than attempt to eliminate mind wandering entirely, we should attempt to alleviate mind wandering at the most strategic times, using research to suggest what techniques should be applied, and when.