So short is love, and so long is forgetting," wrote Pablo Neruda in a testimony to the tenacity of emotional memories. How is it that emotions, positive and negative, strengthen memories for particular events in our lives? At the heart of emotional modulation of memory lies the amygdala, a structure activated by emotional stimuli. It is widely accepted that the basolateral complex of the amygdala (BLA) strengthens consolidation of emotional memories through its projections to widespread cortical area | neuroscience

at least it would explain why people, who work without emotion on the same topic for years seem not to remember a bit, while people who fall in love with a subject develope a nice repository after a while.