People sometimes feel the effect of product consumption almost instantaneously-within an unrealistically short time after consumption. Such placebo-like effects are typically attributed to conditioning, motivation, or expectations about product efficacy. The present research shows such effects can also occur because, under some conditions, people are more prone to underestimate the time to onset of products they have used in the past. These recollections of too short a time to onset alter people's experience of products and cause them to report more rapid effects. Participants who were led to believe there was a strong causal link between having consumed a product and improved performance on a task recalled that less time elapsed before they experienced an effect. In subsequent consumption, they felt comfortable using the product later in time, started working on a similar task earlier upon use, experienced the product's effect sooner, and were less inclined to switch to competing products. (c) 2010 by JOURNAL OF CONSUMER RESEARCH, Inc..