Why do our memories sometimes fade or fail? In this video, I take a trip into my own brain to see how memories are formed, stored, retrieved, and why they are sometimes lost. This video was submitted for the Cognitive Science Society's Mind Challenge contest - and it won first place! Sources Barrett & Zollman (2008). The role of forgetting in the evolution and learning of language. Berry & Davis (2014). Active forgetting of olfactory memories in drosophila. Borges (1942). Funes the Memorious. Camina & Güell (2017). The neuroanatomical, neurophysiological and psychological basis of memory: Current models and their origins. Cohen et al. (1997). Temporal dynamics of brain activation during a working memory task. Davis & Zhong (2017). The biology of forgetting—A perspective. Endress & Johnson (2021). When forgetting fosters learning: A neural network model for statistical learning. Markovitch & Scott (1988). The role of forgetting in learning. Postle (2006). Working memory as an emergent property of the mind and brain. Quiroga et al. (2008). Sparse but not ‘Grandmother-cell’ coding in the medial temporal lobe. Quiroga et al. (2013). Brain cells for grandmother. Tonegawa et al. (2015a). Memory engram storage and retrieval. Tonegawa et al. (2015b). Memory engram cells have come of age.