The emergence of VR as a broadly available consumer technology is driving a renewed need for knowledge on how to enhance presence and design virtual experiences for a broader range of users and use cases that come with VR ubiquity. In prior work, we established an integrative framework for presence expanding the definition from a "sense of being there" to a "sense of feeling real," which can encompass multiple dimensions of presence and interactions amongst them. Here we investigate the role of variations in three variables on the experience of presence in virtual reality: expertise in real-world activities, interaction ability, and the virtual hand ownership illusion. Through immersing users in a commercially available VR environment that simulates rock climbing and utilizing a mixed methods approach, we provide insight into how individual differences in felt presence arise between users. This new work supports our integrative framework and provides methods by which a broader research and design community can extend it and assess differences in users to support the design of immersive experiences which address the components and underlying determinants of individual differences in felt presence in VR. Our results indicate that there exist relationships between expertise in real world tasks and corresponding activity within virtual environments and underlying components of presence including interaction ability and a virtual hand ownership illusion.