Helen Keller best day of her life was when she met her teacher because she taught everything that Helen Keller need to know for language. The first time they meet Helen was sitting on the porch and waiting and the teacher took her inside her house.
Her teacher taught Hellen Keller that different looking things could have the same meaning like doll.
She also taught Helen Keller that a item could have something inside of it like water and mug. Every day Helen would be eager to go to her class everyday.