"That was so fun!" is a phrase that physical education teachers and coaches will likely never get tired of hearing from children. Without fun, youth are unlikely to voluntarily engage in physical activity. While the notion of fun (i.e., enjoyment) in physical activity has been increasingly studied over the past few decades, there has been surprisingly less emphasis given to its counterpart of non-enjoyment, or "unfun." While research findings and practical experience suggest that things such as running laps and not getting to play when on a team are non-enjoyable, little is known about youths' perspectives on non-enjoyment of activity beyond this. In view of American youths' low activity-participation rates, as well as the still-too-high obesity/overweight rates for youngsters, understanding their perspectives on their non-enjoyment of physical activity is an important endeavor. This article describes the results of research activities (a survey, drawing, and focus group and duo interviews) that were conducted with students in grades four, five, and six to elicit their thoughts on non-enjoyment of physical activity. Themes resulting from analysis suggest that lack of skill, an overemphasis on competition and winning, and feelings of pain are major factors hindering children's enjoyment of activity. Contextual factors such as teachers,' coaches,' and classmates' behaviors (e.g., arguing and fighting) during activity sessions also greatly impact youths' enjoyment of activity. Implications for teachers and coaches are suggested.