Humans internalize expectations about how quickly real-world events should unfold: When a tennis serve leaves the racket, we form expectations about how quickly it should cross the court. Here, we tested whether individual differences in such expectations give rise to idiosyncrasies in judging the speed of dynamic real-world videos. Participants viewed 50 videos depicting situations from five different sports. Each clip started at a random playback rate (0.5x–2x), and participants adjusted the rate until it looked most natural. On average, observers selected playback rates below the veridical speed, indicating a general tendency to perceive slower-than-actual speeds as most natural. Individual differences in natural-speed adjustments were reliable: The tendency of a participant to over- or underestimate speed in one half of trials was robustly correlated to their tendency to over- or underestimate speed in the other half of trials. Probing into potential sources of these individual differences, participants also reported their daily exposure to each sport and their time-perception traits using the Individual Time Span Scales (ITSS). Individual exposure to the sports did not predict idiosyncrasies in speed adjustments. By contrast, the ITSS fast time-span orientation was positively correlated with speed adjustments: People who reported a generally faster sense of time chose faster "natural" speeds; people with a slower sense of time chose slower "natural" speeds. Our results (1) reveal robust individual differences in real-world speed perception, and (2) show that these differences are linked to individual tendencies in time-span orientation which may shape expectations about the unfolding of natural events.