There was once a young man who had a terrible motorcycle accident. Though his helmet saved his life, brain trauma left him in a coma. His family gathered around his bedside at the hospital as the doctor told them that there was swelling and damage to his brain, including a small almond-shaped structure called the amygdala. The family waited.

The swelling eventually subsided, and the young man finally woke. The family was joyous. But the nurses noticed the young man was behaving strangely. They cleared the family from the room and asked him what was wrong. He responded,”My family has been replaced by spies.”

Nothing the doctor or nurses said to the young man could shake is belief that the people waiting at his bedside were imposters. “I recognize them all. They’re identical in every way, but they are not my family. They must be spies.”

Neurologists and neuroscientists studied the young man and his unshakable belief that his family was not his family. He recognized his family members and had little trouble recalling events from his life. In brain scans they could see that a crucial, seahorse-shaped brain structure for memory formation, the hippocampus, was relatively undamaged from the accident and subsequent swelling. They came to focus instead on the damage to that little almond-shaped amygdala, a structure that lies at the center of neural circuits progressing emotion. The experts wondered, “What if the young man’s episodic and biographical memories are fully intact through his healthy hippocampus, but the damage to his amygdala erased his emotional connection to those memories? How might one react if you fully recognized those you love most but felt nothing for them?”

Much of the above story is real. There was a man in an accident who came to believe his family had been replaced by spies. Bizarre as it may seem, this disorder is common enough in the annals of neuroscience to have a name: Capgras syndrome. In learning of this syndrome as an undergraduate, it always left me wondering about a profound question at its very human heart: what is love without memory? Do we need both an almond and a seahorse to make a human?

Epilepsy has been a part of Jennifer’s life for as long as she can remember. Her first seizure came at age four, and though she and her family have been able to manage them with medication, frightening attacks still send her to the hospital every few years. Despite the worries of a life-threatening attack, the doctors tell her surgery is not an option. The locus of the attacks is a funny little almond-shared structure too deep in her front lobes for surgical access.

Now in her 20s, Jennifer leads a quiet life focused on her film career. She stays in contact with her parents, though it’s more reflex than love. They worry for her. They worry that one day a bad seizure might kill her, but they also worry that she will be lonely her whole life. Jennifer is kind and funny and smart, but every few years a bad attack seems to hit a reset button inside her mind and wipes away all of her emotional connections. Friendships end; family become mere acquaintances. This has been her whole life, full of memories that evoke nothing.

Then Jennifer met Engin, fell in love, and decided, seahorse and almond, that she would never forget him.