Whilst the above is a nice story I can find no evidence that its true.
The truth appears to be that his school teacher thought him addled and when his mother found out she pulled him out of school and taught him at home.
Similar but not quite the same.
Contrary to popular belief, Thomas Edison was not born into poverty in a backwater mid-western town. Actually, he was born -on Feb. 11, 1847 - to middle-class parents in the bustling port of Milan, Ohio, a community that - next to Odessa, Russia - was the largest wheat shipping center in the world. In 1854, his family moved to the vibrant city of Port Huron, Michigan, which ultimately surpassed the commercial preeminence of both Milan and Odessa....
At age seven - after spending 12 weeks in a noisy one-room schoolhouse with 38 other students of ll ages - Tom's overworked and short tempered teacher finally lost his patience with the child's persistent questioning and seemingly self centered behavior. Noting that Tom's forehead was unusually broad and his head was considerably larger than average, he made no secret of his belief that the hyperactive youngster's brains were "addled" or scrambled.
If modern psychology had existed back then, Tom would have probably been deemed a victim of ADHD (attention deficit hyperactivity disorder) and proscribed a hefty dose of the "miracle drug" Ritalin. Instead, when his beloved mother - whom he recalled "was the making of me... [because] she was always so true and so sure of me... And always made me feel I had someone to live for and must not disappoint." - became aware of the situation, she promptly withdrew him from school and began to "home-teach" him. Not surprisingly, she was convinced her son's slightly unusual demeanor and physical appearance were merely outward signs of his remarkable intelligence.
In school, the young Edison's mind often wandered, and his teacher, the Reverend Engle, was overheard calling him "addled". This ended Edison's three months of official schooling. Edison recalled later, "My mother was the making of me. She was so true, so sure of me; and I felt I had something to live for, someone I must not disappoint." His mother taught him at home. Much of his education came from reading R.G. Parker's School of Natural Philosophy and The Cooper Union.