Michelle Mack has trouble with abstract concepts. She can’t always control her emotions and she’s easily lost in new surroundings. At 27, Mack learned the reason why: she was born with half a brain.

Doctors say Mack, now 37, likely lost the left side of her brain during a pre-birth stroke. Her right side took over many of the functions that the brain’s left side typically controls, leaving Mack largely capable of anything. But some functions frustrated the Falls Church, Va. resident.

“Michelle has fairly normal language abilities, certainly basic language abilities, she can construct a sentence, she can understand instructions, she can find words when she’s talking, but actually she has some trouble in some aspects of visual-spatial processing,” Dr. Jordan Grafman, chief of the Cognitive Neuroscience Section at the National Institutes of Health told CNN.

Nonetheless, Mack graduated high school and today does data entry work from the home she shares with her parents. And, Grafman says, Mack also continues to gain new abilities, reports CNN.