Helen Keller became an activist after gaining her sight and hearing due to her profound understanding of disability and the barriers faced by others. Her experiences with blindness and deafness fostered a passionate advocacy for the rights of disabled individuals and women. Keller worked tirelessly to promote education, accessibility, and social justice, believing that her achievements were possible through support and determination. Her activism included efforts in social reform, suffrage, and labor rights, making her a powerful figure in advocating for marginalized communities.