When you watch a movie in a language you don't speak, do you look for a dubbed version, or do you turn on the subtitles? It makes a difference, because teams who dub movies into another language translate it completely separately from the teams who type up subtitles, which are also used as closed captions. Dialogue in dubbed movies makes an attempt to match the lip movements of the actors. Or sometimes they don't try all that hard, as you've no doubt noticed in some really cheaply made films. And then there's the problem of translating puns, which aren't funny if you just interpret it word by word, or even grammatically, if the context doesn't make sense in another culture. If you listen to a dubbed movie and turn on the captions, too, you might notice a lot of differences, which will cause you to lose the plot quickly. The last minute of this video is an ad.
Also, of course, there's the famous, "You see what happens when you find a stranger in the Alps, Larry! You see what happens when you feed a stoner scrambled eggs!" in /The Big Lebowsky/.