Isn't the intro (on the film version) a little variation where it starts on the I (not sue how many bars), but then goes IV, IV, I, I, V, IV, I (instead of bars IV, IV, I, I, V, V, I)...
Sorry, don't know myself if that makes sense? A bit like last night really. Oh, and I'm not allowed to count bars - "you should just feel it"...