2 people bested this!
In the movie "E.T.," Elliott, played by a then-eleven-year-old Henry Thomas, is lonely after the divorce of his parents. E.T., of course, is all alone and terrified when he's inadvertently left behind on Earth.
He and Elliott are fortunate to find each other and become friends. Elliott does his best to protect E.T. and ultimately help him return home – before the government discovers him. After E.T. constructs his communication machine in order to contact his home planet, Elliot goes with him to the forest to use it, and when E.T. expresses how homesick he is, Elliot tells him he can stay on Earth and they can grow old together, even though Elliot knows this sadly isn't true.
Soon thereafter, E.T. becomes so sick he begins to die, and because of the psychic connection he shares with him, Elliot begins to die, too. E.T. realizes Elliot has a family that loves him, and so, despite Elliot's pleas for E.T. to stay with him, E.T. lets himself die in order to spare Elliot. But somehow, it turns out E.T. is alive after all, and he confirms to Elliot that his people are on their way back to Earth right now to bring him home. Later, when E.T. finally does get picked up by his people, he invites Elliot to come with him, but both E.T. and Elliot know that Elliot must remain on Earth with his family.
It's bittersweet when, at the end, E.T. and Elliott must part ways forever, but even though they're many light-years apart, they'll always be dear friends, and E.T. will never, ever forget Elliott nor what he and his family did for him during his time on Earth.