It seems that surprise events have the potential to turn short-term memories into long-term memories, an unusual phenomenon that may have limited but interesting applications in learning tasks. This surprise-enhanced cognition phenomenon is theoretically modeled based on the notion that many human mental traits have evolved through natural selection; a mathematical analysis building on Price's covariance theorem is employed in this modeling effort. Additionally, the phenomenon is discussed in the context of an online learning task, based on a study involving 186 student participants. A simulated threat was incorporated into a human-computer interface with the goal of increasing the interface's knowledge-transfer effectiveness. The participants were asked to review Web-based learning modules and subsequently take a test on what they had learned. Data from six learning modules in two experimental conditions were contrasted. In the treatment condition, a Web-based screen with a snake in attack position was used to surprise the participants; the snake screen was absent in the control condition. As predicted, the participants in the treatment condition did significantly better in the test for the modules immediately before and after the snake screen than the participants in the control condition. These findings are extrapolated to classroom applications in general. Ethical considerations are also discussed.