When we first meet John, the storytellers really play up just how terrible he is with people, and women in particular—to the point where we seriously doubt that he'll ever have a love life.
And then Alicia walks into his classroom, and that all changes.
She's Not Afraid of John…and She Doesn't Mind His Quirks
Even though John is a) super awkward and b) her instructor, Alicia is not the least bit intimidated by him. Once she decides she likes him, she goes to his office hours and asks him out:
ALICIA: I'm wondering, Professor Nash, if I can ask you to dinner. You do eat, don't you?
JOHN: Oh, on occasion, yeah. Table for one. Prometheus alone, chained to the rock with a bird circling overhead, you know how it is. No, I expect that you wouldn't know. If you leave your address with my office, I'll pick you up Friday at 8:00, and we'll eat.
Alicia totally seems to dig John's awkward chatter and directness—and as you can tell, she's fairly direct herself.
In fact, even when John is super forward about just wanting to cut to the chase and get to the sexual part of their relationship, she doesn't find it crass or off-putting:
JOHN: I have a tendency to expedite information flow by being direct. I often don't get a pleasant result.
ALICIA: Try me.
JOHN: All right. I find you attractive. Your aggressive moves towards me indicate that you feel the same way. But still, ritual requires that we continue with a number of platonic activities before we have sex. I am proceeding with those activities, but in point of actual fact, all I really want to do is have intercourse with you as soon as possible. Are you going slap me now?
ALICIA [kisses him]: How was that result?
So, yeah, he's definitely found himself the right girl.
From Understanding Girlfriend to Very Understanding Wife
Things aren't all flowers and roses for John and Alicia, though. As it turns out, John has schizophrenia, which means he suffers from delusions that definitely interfere with his everyday functioning. Like, to the point where he and his doctor worry for Alicia's/their baby's safety when John goes off his meds and really doesn't want to go back on, even after a particularly emotional and scary episode:
JOHN: […] You shouldn't be here. I'm not safe anymore.
ALICIA: Would you have hurt me, John?
JOHN: I don't know. Maybe you should let Dr. Rosen drive you to your mother's.
Alicia appears to take his advice and leave, but she ends up coming right back—apparently, it takes a lot more to scare her off.
ALICIA: Rosen said to call if you try and kill me or anything.
Er, yes, definitely pick up the phone in that case, Alicia. But anyway, you get the picture: She's not easily scared or intimidated, and she's pretty devoted to John. She even agrees to help him make a go of life without the meds—even though his doctors want her to commit him against his will—and take a leap of faith with her husband:
ALICIA: I need to believe that something extraordinary is possible.
It totally pays off, too. John manages to keep the delusions at bay enough to function and even start working again, and when he receives the Nobel Prize years later, he uses his acceptance speech to give her a shout out for her crazy levels of devotion:
JOHN: My quest has taken me through the physical, the metaphysical, the delusional, and back. And I have made the most important discovery of my career. The most important discovery of my life. It is only in the mysterious equations of love that any logical reasons can be found. I'm only here tonight because of you. You are the reason I am. You are all my reasons.
Swoon. That's pretty romantic, if you ask us. Who would have guessed that John could ever be that lovey-dovey? Not us, but it's no hallucination: John completely hearts Alicia.