I couldn't tell how many times, but surely not 300 times either.
It's funny : now I remember that once my cousin was watching it when we were there. And he told me, "It's Forrest Gump, you know that movie don't you ?" And I said something like : "Yeah, the movie where they say 'run Forrest, run'. I've seen it once or twice'".
Now.. well I may have seen in 6 or 7 times, and sometimes I watch only a few scenes not the entire movie.