For example, if in 1990 a person willfully concealed a mortal sin in confession, all his confessions and Holy Communions are sacrilegious until he makes a good confession in which he tells of his sacrilegious act. If a person forgets to confess a mortal sin in confession, his confession is not sacrilegious. All that is necessary is that he tells this particular mortal sin in a future confession whenever he thinks of it