The objective of the present essay is to clarify the nature of so-called `occurrences' by attributing distinct modes of existence and persistence to processes and events. In doing so, we break away from the perdurance theory claimed by DOLCE's authors, and we distance our self from mereological analyses (such as those recently used by Guarino to distinguish between `processes' and `episodes'). In line with the work of Stout and Galton, we first draw a parallel with how processes and objects endure by proposing that processes have a dynamic presence (contrasting with a static presence for objects). Next, we give events the status of abstract entities by identifying them with objects of thought (by individual or collective subjects). This allows one to distinguish between the existence and occurrence of events. We therefore define the latter as psychological or even social endurants, which may occur contingently.