Curiosity during learning increases information-seeking behaviors and subsequent memory retrieval success, yet the mechanisms that drive curiosity and its accompanying information-seeking behaviors remain elusive. Hints throughout the literature suggest that curiosity may result from a metacognitive signal—possibly of closeness to a not yet accessible piece of information—that in turn leads the experiencer to seek out additional information that will resolve a perceptibly small knowledge gap. We examined whether metacognition sensations thought to signal the likely presence of an as yet unretrieved relevant memory (such as familiarity or déjà vu) might be involved. Across two experiments, when cued recall failed, participants gave higher curiosity ratings during reported déjà vu (Experiment 1) or déjà entendu (Experiment 2), and these states were associated with increased expenditure of limited experimental resources to discover the answer. Participants also spent more time attempting to retrieve information and generated more incorrect information when experiencing these déjà vu-like states than when not. We propose that metacognition signaling of the possible presence of an as yet unretrieved but relevant memory may drive curiosity and prompt information-seeking that includes further search efforts.