"I could talk about the millions of lives Jo has enriched whether through the stories and characters she's created or through the millions of pounds she's given to charity. She's a remarkable woman. However, I would like to thank Jo for changing MY (sic) life. Without her imagination and her talent I would never have become the man I am today." HARRY POTTER star Matthew Lewis, who played Neville Longbottom in the movies, writes a heartfelt tribute to J.K. Rowling to mark her 50th birthday on Friday (31Jul15).