A recent study in PLOS Biology explored how positive scent memories from early life form, survive, and change inside the brain. Nearly three-quarters said the original experience had occurred more than five times, suggesting that childhood scent memories often grow through repetition. However, brain regions began fluctuating together in a pattern unique to mice recalling the positive childhood scent. Still, the model captures several features that make early scent memories distinctive: pleasure, repetition, persistence, and emotional force. A childhood scent begins among neurons that matured near the start of life.