It's quite difficult to come out of a movie and judge it as a full, beginning-to-end experience. We're naturally more inclined to remember key moments or sequences, and more often than not, it's these bits that inform our opinion of the movie overall.
And while that doesn't necessarily make these standout moments bad, it does mean that the rest of the movie's runtime can go without the high praise it might deserve.
What does everyone talk about after they watch Inception? Whether Cobb's spinning top actually fell over or not. Se7en? The "what's in the booox!" scene, and the grisly revelation it results in. The Silence Of The Lambs? Anthony Hopkins' electric, Oscar-winning performance. Sometimes, these parts of a movie are all people will remember, leaving many other great scenes, acting displays, or other areas criminally - and unfairly - underappreciated.
We're all guilty of this, and more than likely, you too define one of the following movies by their one standout aspect, whether that's a single scene or a laughably bad performance. Just don't forget how good the rest of it is!