If you were born on Tuesday, November 26, 1940 then Set Adrift on Memory Bliss by P.M. Dawn was the number one on your 51st birthday, and went to number one on November 24, 1991. Check the price of Set Adrift on Memory Bliss by P.M. Dawn on Amazon.com
The biggest selling book of 1991 (the year you turned 51) was Scarlett: The Sequel to Margaret Mitchell's "Gone with the Wind" by Alexandra Ripley.