Dr. Francis Crick (1916-2004) knew a lot about the human body. He got the Nobel Prize in Physiology in 1962 for co-discovering DNA.
Almost 30 years later, he made another discovery, as Dr. Terrence Sejnowski recalls in an interview. Francis Crick discovered that a model (i.e. plastic) brain that had been sitting in his office for decades, and that he had used numerous times as a learning and teaching tool, was in fact much bigger than a real human brain. He never realized that. Yet any four-year-old could have noticed that the model brain was much bigger than anyone's whole head.
Not the first time we notice a Nobel Prize winner Being Human.