Answer: The most important day I remember in all my life is the one on which my teacher, Anne Mansfield Sullivan, came to me.
Explanation: It was the third of March, 1887, three months before I was seven years old. The most important day in Helen Keller's life, according to her, was the day Miss Sullivan arrived. Keller writes: The most important day I remember in all my life is the one on which my teacher, Anne Mansfield Sullivan, came to me.