Might introduce key characters!
This is the first actor mentioned in the opening. Guy Pearce plays the protagonist in 'Memento', naturally, it is his name at the top of the list of actors.
Carrie-Anne Moss plays the character of Natalie in the film. Her name comes after the protagonists name. Although she does play a big part in the storyline, she is not as important.
Joe Pantoliano is the third most important character. He is also quite a big character in the movie but, again, is not as important as the other two, therefore his name comes last in the list of key actors.
Of these three main actors, only Guy Pearce (the protagonist) is actually featured in the opening to this movie. The back of Joe Pantoliano's head is right at the end of the opening. The fact that the opening only features the protagonist outlines just how important he is.
However, in 'What Lies Beneath' none of the titles include actors names. We are introduced to the protagonist straight after the titles, so we then know that Michelle Pfeiffer will be starring in the movies.
Our introduction to actors and characters started with "Starring Ben Bezzina". We started with Ben because his character was more dominant than mine, therefore his name came first.
Although my character was not dominant, she was still a key character.