Social distancing measures have been implemented in many countries to limit the spread of COVID-19. Emerging literature reveals that fear of acquiring COVID-19 has detrimental psychological ramifications. However, it seems likely that social distancing will have a further negative impact on well-being. The focus of this study was therefore to investigate whether changes in behaviour as a result of social distancing would predict changes in well-being. Participants (n = 95) rated their level of well-being as it was both during social distancing and retrospectively one month before beginning social distancing. Participants also indicated how much time they spent engaged in various activities both during social distancing and one month before social distancing and nominated how important each of these activities was for them. These measures employed scales created specifically for the present study. In addition, participants completed the Big Five Inventory–2 Extra-Short Form and the nine-item version of the Personal Optimism and Self-Efficacy Optimism Scale. We found that affectivity–both positive and negative–decreased with increased engagement in meaningful activities and that affectivity increased with increased activity in general. While both sorts of activity appear to improve some aspects of well-being, it appears that meaningful activity regulates psychological homeostasis while busyness in general does not.