He was born on 28 July 1949 in Nugegodaas the fourth child of the family with 6 siblings. He completed education from St. John's College, Nugegoda. He has three brothers and two sisters. His brothers, Nimal Kuruwita Bandara is a lawyer and Thilakaratne Kuruwita Bandara is a journalist and editor.
He sat for General Certificate of Education (GCE) Ordinary Level in 1963. After passing senior examination, he was selected to Vidyodaya Pirivena (currently known as University of Sri Jayewardenepura) for higher studies. In 1971, he obtained a Sinhala honours degree with a first class.
He worked as a temporary lecturer at University of Kelaniya in 1972. Then he served as a Part time lecturer at The Department of Aesthetics studies at Kelaniya university from 1975 to 1976. He moved to University of Jaffna as a Lecturer of Sinhala in 1976 and worked as a lecturer for three years. Then he returned to Kelaniya as a permanent Assistant lecturer. In 1985, Ariyaratne joined the academic staff at the University of Sri Jayewardenepura where he was promoted as an Assistant Professor and became a professor in 1994. In 1989 he traveled to Madras to study Tamil. In 2000, he was promoted as a Senior Professor of Sinhala Language and Mass Media in the Communication Faculty, becoming the youngest to achieve the feat in Sri Lanka university system.
In 2011, he was awarded Doctorate in Literature from Kelaniya University. In 2015, he was honored with second Doctorate in Literature in recognition of his contributions in the field of literature and the arts.
