Our hero, Leo Finkle, is what our mothers usually refer to as "What a nice young man." He's studying to be a rabbi, which means his life is pretty scholarly and solitary:
[…] but for his parents, who had married comparatively late in life, he was alone in the world. He had for six years devoted himself almost entirely to his studies, as a result of which, understandably, he had found himself without time for a social life and the company of young women. (3)
No wild n' crazy spring breaks for Finkle. All work and no play has made Leo a dull (and lonely) boy. In fact, his lonelyhearts status is why he hires Salzman to find him a match… and why the whole dang story kicks off.
Loneliness plays a huge part in Leo's life. He has no friends, he has no family nearby, and in fact the only people he interacts with are Salzman the matchmaker and the girls he gets set up with. We assume (or at least really, really hope) that he talks to his parents on the phone, and maybe some rabbis-to-be at his school, but we don't see that in the story. As far as we can tell, he's Mr. Lonely.
Part of Leo's journey in this story is first discovering his loneliness and then determining to do something about it. You can see his first big realization after his strained conversation with Lily Hirschorn:
It seemed to Leo that his whole life stood starkly revealed and he saw himself for the first time as he truly was--unloved and loveless. (114)
Ouch. That's a lot to absorb. This realization makes him miserable, and he can't quite fight his way out of his funk… until he finds Stella's picture. Maybe it's a byproduct of his loneliness that he thinks, "Only such a one could understand him and help him seek whatever he was seeking" (143) when he sees her tiny photo booth snapshot.
He has a pretty strong reaction to looking at her picture, but if you consider the realization he had (he's loveless and unloved)—and the fact that his efforts to find anyone on his own have been miserable failures—then we can understand why he might decide to put all of his love eggs in Stella's basket. Erm. That sounds kind of wrong, doesn't it?
But, this being the titular (tee hee: our inner middle-school student always snickers at that word) story in a National Book Award-winning collection, Leo's emotions are going to be a little more nuanced that just "I'm sad, womp womp. I need a wifey."
Initially, Leo doesn't want a wife because he's a romantic, only because "he might find it easier to win himself a congregation if he were married" (1). His heart isn't in it, at least at first. He's addressing vague concerns about his career and his overall loneliness.
He's also looking to patch up his relationship with God, which is pretty ambivalent:
"I think," he said in a strained manner, "that I came to God not because I love Him, but because I did not." (111)
Yikes. He decided to become a rabbi because he didn't love God… which is kind of like becoming a pilot because you're scared of flying. In time, though, he comes to suspect that the two issues are interconnected, that "that he did not love God so well as he might, because he had not loved man" (114). He thinks that by finding a bride, he can find a real connection to (and love for) God. That comes to a head when he sees Stella's picture and "He picture(s), in her, his own redemption" (201).
Quick recap: he goes from wanting a wife in order to further his career as a rabbi (even though he has some super-ambivalent feelings about God) to getting a wife so he can learn to love man and, by extension, God. Holy 180, Batman.
We've already addressed Leo's loneliness and his issues with loving God. But it takes some good in-scene action between Leo and Salzman to see the full extent of the change in Finkle's character. Because Leo ain't the nicest dude towards Mr. Matchmaker Salzman at the beginning of the story.
When Leo is in his "Gimme a wife so I can be a good family man rabbi" phase, he sees Salzman as merely a salesman. He thinks of Saltzman as pushy, deceitful and machinating. How interesting—when Leo is being machinating and looking for decent wife material instead of love, he dislikes Saltzman.
But when Leo has realized that the path towards God is through human connection (a.k.a. a love life) he starts to be kindly and more openhearted towards Salzman. Dang. Could it be that our protagonist is opening himself up to not only pretty girls, but to fishy-smelling old matchmakers?
Leo comes to believe that we find God in our interactions with other people; if we cut ourselves off from them, we cut ourselves off from God. Naturally, there are no guarantees of this being true… but it does fill Leo with hope. It also helps him evolve from being a completely isolated person to someone excited and interested in interacting with other human beings.
In that sense, it doesn't matter whether he finds true love with the elusive Stella. He's grown as a person, and ends the story with more resolve and commitment to his path than when he started. Aww, shucks. If that's not a happy ending, it's at least a hopeful one.