Rose Marie Bentley lived a rich, full, but relatively ordinary life, according to ABC News. She raised a family and volunteered during World War II, according to CNN. All the while, she never knew that she was a living medical rarity.

Bentley’s unique medical condition was discovered after her death. She, like her husband who had died over a decade before her, donated her body to science. Her body was gifted to Oregon Health & Science University, where it was used as a teaching aid for medical students.

When he got called over to the cadaver, assistant professor Cameron Walker assumed that his anatomy student was just having a difficult time.

Walker was surprised to see that his student wasn’t this issue – Bentley’s organs were actually reversed, each in a position mirroring where organs are typically found. It’s a condition called levocardia with situs inversus, and it affects just 1 in 22,000 babies.

Along with her organs being on the opposite side of the body than you might expect, she also had veins that were in unusual places, and her right lung had two lobes rather than three.

Most babies born with the condition also have severe heart defects, leading to a low survival rate. It’s extremely rare for someone with the condition to live until almost 100. Bentley never even had any serious symptoms, except for acid reflux. Even though her gall bladder was removed and she had a hysterectomy, doctors never realized her condition.

Her family thinks she would have been tickled about the whole thing.