You have not been in touch with your ex girlfriend.  You suddenly realized that you want to be in her life again.  You want to try to have a relationship with her.There are ways on how to win your ex girlfriend back even though you have been separated for a year or more.  You need to find a way on how to talk with her.  Try to email her or call her.  Just say a simple hi.  Do not be scared because this is one way to show that you are present again in her life.  Try to show that you want to go out with her again and that you care for her.