When 30-something Italian immigrant Franco Magnani arrived in San Francisco in the 1960s, he came down with just such a fever -- to the point that he sometimes became delirious and had seizures. In the aftermath, Magnani started having insanely vivid dreams/memories about his childhood hometown of Pontito, Italy. The man hadn't visited the place in more than 30 years, but his dreams were intense and filled with detail, as if his seizures had somehow surfaced a bunch of old image files off his brain's hard drive, perfectly intact.
Magnani became so engulfed by the memories that he started to draw and eventually paint them. If the below paintings look like random pictures of streets and alleys you could see on anybody's wall, you have to see them next to a photo of the real scene to understand why they're remarkable. The photo is on the left. The painting on the right was painted from a three-decade-old memory from early childhood: