As an inexperienced nonprofessional voice actor, I really don't understand why those professional ones always add those annoying extra lines, especially off-the-script irritating jokes, in Thai dubbed films; mostly Asian films. Still doubting if this is the right way to follow as Thai film-goers seem to like this dubbing method, but indeed it totally bothers me as it really insults the film itself - and your jokes are utterly dull. sigh.