Phillip K. Dick?
The original novel was by George Clayton Johnson and William F. Nolan
The book was way different than the Movie and had some pretty cool concepts such as the computer that controlled everything underneath Crazy horse Mountain and Dome cities all over the world which were accessed via a tube train.
21 was the age for last day.
Johnson is doing Jessicas run which should be released shortly
Yes, sorry, was having a Total Recall lack of recall.