That bittersweet ache you feel when scrolling through old photos or hearing a song from your teenage years isn't just sentimentality—it's your brain engaging in one of humanity's most sophisticated psychological processes. Nostalgia, once dismissed by psychologists as a mental disorder, has emerged as a powerful cognitive tool that shapes our well-being, relationships, and sense of purpose in ways that continue to surprise researchers.
The Neuroscience of Looking Back
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