The universe, at times, has a very sick sense of humor. Laurel has been thinking about Nathan, how weird but not unpleasant her conversation with him had been, and about the woman she'd dreamed she'd been since she was a girl.
And Laurel finally admitted to herself that, deep down, she was irrationally afraid of falling for a man who didn't love her back. But Jim was not, in any conceivable way, the man she'd dreamed about. If that were even possible, which it wasn't.
She felt more than a little stupid, calling him, but she would feel worse if she wondered, for weeks, whether there was anything going on or not, and was finally forced to concede there wasn't when enough time had passed. She hoped it wouldn't come to that. She liked him - she wanted this to work.
So, thanks to Nathan, her dreams, and the sense of upheaval both have caused... she's listening to Jim's phone ring, telling herself that she is an adult woman and that there's no need to feel like she's seventeen again.