History TearJerker / Up

Another possibility is that Russell lives with his mom and Phyllis is the dad's new girlfriend or wife.

* It's depressing to realize what Muntz threw away. He was still a very young man, at the peak of his prime, famous, idolized and presumably extremely rich. He missed out on what could have been a life of incredible success, comfort and renown if he would have just let the bird scandal go. Instead he literally spent the rest of his life alone on a fool's errand, trying to fulfill a quest that nobody remembered or cared about in present day.

* The ''intro.'' The lives of two people very much in love, from their youth 'til they are parted by death -- complete with the shared dream they were never able to complete. The creators were worried that the old man's reasons for going on his fantastic voyage would appear to be suicidal -- "he just wants to join his wife".

** Note that Mick [=LaSalle=] of the ''San Francisco Chronicle'', who thought ''WesternAnimation/WallE'' could stand to be half an hour shorter, was [[http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/05/28/MV6617S4LC.DTL pretty much blown away by that intro]].

** To see Carl, after repetitively telling Dug "I'M NOT YOUR MASTER!" and even insulting him unfairly earlier on, accept and give back the retriever's affection (and giving us the final proof he's finally moving on), is enough to make person weep with happiness.

* After rescueing Russell and Kevin, Carl watches the house floating downward and disappearing beneath the clouds, seemingly lost forever.

* It's depressing to realize what Muntz threw away. He was still a very young man, at the peak of his prime, famous, idolized and presumably extremely rich. He missed out on what could have been a life of incredible success, comfort and renown if he would have just let the bird scandal go. Instead he literally spent the rest of his life alone on a fool's errand, trying to fulfill a quest that nobody remembered or cared about in present day. ** Even worse is looking at it from Muntz's perspective. He most likely thought the expedition would take a few months, maybe a little over a year at the longest, and he would be vindicated. Instead, the bird turned out to be so elusive that it took him his whole life to find it, and the failure to do so gradually wore away at his sanity.

*** Or a third option: Phyllis is an older sister who’s been PromotedToParent.

** For more specifics, the moment when Ellie goes into hospital and pushes the Adventure Book into Carl's hands. The sheer disbelief and grief in the look he gives her, since she's just told him, still without dialogue, that she isn't going to make it... And it crosses with Heartwarming, but it's also obvious that these two have spent their entire lives together, with her even joining him at work at the zoo. To say Carl will feel like a spare part without Ellie is an understatement.

** He cleans up his living room and sits in his armchair, only to quickly realise that Ellie is not there to share this moment with. Especially after he picks up her Adventure Book once again, and gets to the "Stuff I'm Going To Do" page.