Let’s define ‘our time’ as the period between when human history records began and now. Even with such a general definition, this premise is also questionable. It might be, for example, that time-travel is developed, but only developed enough to allow random time-travelling, and not to specific locations in time which the future humans choose. If so, it seems perfectly possible that future humans, popping randomly into the past, never hit our time at all, and have to make do with some dinosaurs for company instead. After all, ‘our time’ thus defined is only a tiny region of the available pool space in which a time-traveller can plunge.