In cognitive psychology it is well known that cognitive load can have a significant impact on time perception. In this paper, we present an observation made during an empirical evaluation of several input techniques, showing that the cognitive load occurring during user input can significantly reduce perceived time. We provide a discussion of our findings, proposing that existing work in cognitive psychology, such as the Cognitive-Timer Model is applicable to HCI; and that this understanding can provide valuable information for predicting and actively modeling perceived input performance when designing user interfaces.