Although we like the guy, even we must admit that T.S. Garp can be a bit insufferable at times. As we come to learn, Garp struggles to empathize with people outside his close-knit community. His challenge, then, is to peel back his defenses like layers of an onion. Now let's peel back a few layers of our own to see what's really up with our protagonist.
Garp has it all: He's handsome, intelligent, and charming. But that doesn't mean he's perfect. In fact, he lacks something big—empathy—which is a little ironic since he's the son of the super selfless Jenny Fields. We can't help but think back to young Randy telling Garp that he should be "more generous" (14.91) with how he shows off his superiority. Even Helen, who loves Garp more than anything, knows how much he "made people […] angry" (19.54). Try putting yourself in somebody else's shoes for a minute, dude
But as off putting as he can be to people he doesn't really know, it's not like Garp is always an angel to those he does know well, either. When it comes to Helen and his family, for instance, Garp convinces himself that he can "spare [...] others the consequences" (18.316) of his affairs, but we all know that this isn't the case. Even Mrs. Ralph can see, in one conversation, that Garp doesn't treat Helen with the compassion that she deserves.
Garp, on the other hand, doesn't receive this memo until Helen's affair (and the subsequent accident) forces him to. But sometimes tragedy is exactly what we need to wake up to reality.
It's only by being humbled in this way that Garp is able to change his tune. He pretty much goes along doing as he likes until Helen gives him a taste of his own medicine by having an affair of her own. This is his first big wake-up call, and importantly, it sets a series of pretty sizable changes in motion.
The first change comes early on in Garp's stay at Dog's Head Harbor after the family's accident, when he manages to "smile" (14.54) and get along with Ellen Jamesians, of all people. Instead of being annoyed by them, he's able to recognize a small bit of similarity: They all have to communicate via notes, the Ellen Jamesians because they have no tongues, and Garp because he's been hurt in the accident. His later encounter with a rogue Ellen Jamesian—in the form of a failed assassination attempt—removes his last defenses once and for all.
With this, Garp becomes a different person, practically overnight. He is now "suddenly generous in all matters concerning the Fields Foundation" (18.378)—a stark contrast to his previous attitude. If he thinks that an applicant sounds "sincere" (18.378), then he just goes ahead and gives them grant money without a doubt. This is a far cry from the judgmental Garp we've come to know and love.
Furthermore, Garp starts writing again—his next novel is titled My Father's Illusions. Although Garp never knew his dad, he does know a thing or two about having illusions shattered. After all, in some ways, his years of self-absorption and distaste for others were a kind of illusion in their own right: As it turns out, Garp is much more capable of kindness and empathy than anyone (us as readers included) has ever suspected.
Everything is perfect now, right? Well, we wouldn't go that far. Although this new Garp seems wonderful, he and Helen can't help but feel the "Under Toad" (18.355) creeping up behind him. But Garp isn't as afraid anymore—his crazed paranoia has fallen to the wayside along with his lust. But if we've learned anything from Garp's own stories, it's that this one can't have a happy ending.
If there's any solace we can take from his death, it's that it comes at the most open and honest point in his life. Even his fear—which has crippled him at various points—gives way to a feeling of peace. Even though he'll be gone, he knows that there will be "life after Garp" (19.50). Now, if that's not the ultimate expression of empathy, then we don't know what is.