When observers memorize different layouts of similar stimuli, their memory performance declines across trials. However, note-taking during the first trials prevents such a decline also in an unaided final trial. This effect was attributed to intentional forgetting of the preceiding stimuli (Eskritt & Ma, 2014; Memory & Cognition, 42, 237-246). We argue that the beneficial effect of note-taking on memory performance in the final trial emerges either from a release from proactive interference between subsequent materials or a release of mental fatigue. In two experiments, we aimed at disentangling these two explanations using a Concentration Game paradigm. In the first experiment (N = 53), we replicated the effect that internal memory performance was more accurate in a final (unaided) round of the concentration game (repeating the same pairs of cards) when the participants were allowed to take notes during the first rounds than when they had the solve the game without note-taking. In Experiment 2 (N=87), we varied whether the pairs of cards were repeated or novel stimuli. We observed that the beneficial effect of note-taking occured only for repeated pairs of cards, but not for novel pairs of cards. This finding suggests that note-taking released observers from proactive interference, but does not improve subsequent memory in a broader sense.