As metaverse becomes one of the most popular buzzwords in technology, there is still a lack of support to integrate true metaverse learning experiences in massive open online courses (MOOCs). This article introduces a new framework of massive open metaverse courses (MOMCs) and its major enabling technologies, which add immersive and 3-D learning experiences lacking in MOOCs. It then describes a detailed case study, the President's First Lecture at the Hong Kong University of Science and Technology (Guangzhou), which we consider the world's first true MOMC environment, enabled by the latest volumetric video and related virtual and augmented reality technologies. We describe in detail how this course is created and discuss the major advantages of MOMC over MOOC as well as its current limitations.