Robert Pattinson can't remember his lines.

The 'Remember Me' actor admits he constantly needs someone on set to help him with scripts as he has such a poor memory.

He said: "When we do 'Twilight' there is always someone there who takes care of everything and feeds you your lines. I read a lot on set, but as soon as I shut the book I can barely remember the last line I've just read."

Robert, who is currently working on drama movie 'Bel Ami' with Uma Thurman and Christina Ricci, says his problem has been highlighted while making the film because director Declan Donnellan is more used to working with stage actors and expects the same levels of dedication from his screen stars.

He told Germany's Focus magazine: "We're just shooting 'Bel Ami' and Declan Donnellan is directing it. He usually does stage productions and expects me to know all of my lines - like a stage actor.

"No chance! I realised how rusty and slow my brain has become."

Robert has previously confessed to having to take part in "disturbing" sex scenes in 'Bel Ami'.

He said: "The sex scenes with Uma are disturbing. Her character uses sex as a weapon and my character thinks like an animal."

'Bel Ami' is currently filming and has a preliminary release date of 2011.