Smartwaches are the representative wearable or body-worn devices that provide convenient and easy information access. There is a growing body of research work on enabling novel interaction techniques and understanding user experiences of smartwatches. However, there is still lack of user experience research on wearing behaviors of smartwatches, which is critical for wearable device and service design. In this work, we investigate how college students wear smartwatches and what factors affect wearing behaviors by analyzing a longitudinal activity dataset collected from 50 smartwatch users for 203 days. Our results show that there are several temporal usage patterns and distinct groups of usage patterns. The factors affecting wearing behaviors are contextual, nuanced, and multifaceted. Our findings provide diverse design implications for improving wearability of smartwatches and leveraging smartwatches for behavioral changes.