"We're gonna ride through town, in one of those new horse-drawn open cars […] And we won't come home until we've kissed a girl."
This verse of the song from Hello, Dolly, which opens the movie, is ironically being juxtaposing a horse drawn car to a flying robot. It also foreshadows WALL-E and EVE's romance. WALL-E even gets to "kiss" the girl, as we'll see later on.
"And we'll recall when time runs out, that it only took a moment to be loved. A whole life long."
The Hello, Dolly song isn't just a soundtrack choice. WALL-E has a copy of the VHS tape, which he watches in his little house. And he doesn't just watch it: WALL-E hits record on his chest and records the song. He wants to carry this desire for love wherever he goes.
[WALL-E follows EVE as Louis Armstrong's "La Vie En Rose" plays]
When EVE appears, we're treated to a song that is just a soundtrack choice (as far as we know, WALL-E isn't a big Louis Armstrong fan), but it's a good choice. One of the lyrics is "I'm in a world apart, a world where roses bloom." WALL-E has never felt a feeling like this before. And, needless to say, his world doesn't have any roses—but it does have a little sprout in an old boot.
[WALL-E swoons when EVE says his name.]
Even though WALL-E doesn't even have a unique name (WALL-E is more like a model number, if anything), he still seems to swoon when EVE pronounces it, because now she knows who he is. The fact that she doesn't try to kill him this time helps.
[When EVE shuts down, WALL-E sets her in the sun and attaches jumper cables to her.]
WALL-E will do anything to get EVE back when she shuts down, like Prince Charming trying to wake Sleeping Beauty. WALL-E is smart enough to try everything that gives him energy, but he can't even comprehend what might make EVE tick. The gulf between the sexes exists even in robots.
[When WALL-E can't fix EVE, he sadly compacts trash.]
WALL-E is heartbroken when EVE won't revive, and you can tell he's sad by the way his eyes tilt down on the sides. WALL-E's binocular eyes are the way to his soul. When EVE does revive later, WALL-E's vision gets all foggy the first time he looks at her.
[EVE zaps WALL-E with a kiss in space as John and Mary remark,] "Oh, so many stars."
The little spark that passes between them is both a literal spark and the figurative spark of robo-love.
[John and Mary accidentally touch hands.]
As John and Mary watch EVE and WALL-E's little space-dance of love, they start falling for each other almost immediately as well. Love is in the air… well, if space weren't a deadly vacuum, love would be in the air. It's in there somewhere, though.
CAPTAIN: "Computer, define "dancing."
COMPUTER: "Dancing, a series of movements involving two partners where speed and rhythm match harmoniously with music."
As WALL-E and EVE "dance" in space outside the ship, the Captain starts researching Earth. He falls in love with the idea of returning home to Earth, which, to him, seems to be a place of pure joy.
[Right before EVE's kiss brings back WALL-E's memories, she hums] "It only takes a moment."
EVE hums the song that says "And that is all that love's about, and we'll recall when time runs out. It only took a moment to be loved. A whole life long." It's tough to tell whether it's her humming, her little kiss, or a combination of the two that jogs WALL-E's memories, but whatever it is, we're glad he got them back.