Even after just one episode of Big Little Lies, there are already a lot of questions. It is clear that one of the series' protagonists, Jane, is not revealing something from her past. But what happened to Jane in Big Little Lies? Something traumatic seems to have happened to her. To recap: She's a very young, single mom, living in a small, one-bedroom house, in a neighborhood where all of her friends and neighbors are in huge multi-million dollar homes. When Madeline asks her what brought her there in the pilot, she doesn't really give a straight answer. And there are a few moments where it looks like she's experiencing a traumatic flashback, running down the beach in a blue dress, then, later, upset and disoriented while wearing the same dress.
For those who've read the book version of Big Little Lies that the show is based on, there's a concrete answer to what's plaguing Jane, and it is part of what motivated her to move to Monterey and why she's having those flashbacks. This post has serious book and show SPOILERS below, so beware if you want to remain in the dark along with the TV timeline and find things out in accordance with each episode.
So, the book reveals that Jane was sexually assaulted during a hookup with an older man, which resulted in her pregnancy with Ziggy. Now, six years later, she's hoping to track him down, while still struggling with the trauma of being raped. Jane's phone call with her concerned mother, who wishes she would return home to Santa Cruz, is already setting up that Jane has an ulterior motive behind her move to the new town. Now, to reveal much more than that would be too much after just a single episode, but the book goes on to draw some parallels between what happened to Jane and everything else that's going on underneath the seemingly peaceful exterior in Monterey.
The pilot did a good job subtly reinforcing some of those connections. Jane's nightmare is intercut with the moment when Celeste's husband, Perry, grabs her, a moment of domestic violence that will bond the two women as the story continues. And in the ending, where Madeline finally attempts to quiet her mind and go to sleep, there are some shots that could also be memories of Jane's assault, with struggling limbs visible in what looks like a car. Some of the imagery is still kept purposefully ambiguous, but it looks like the TV adaptation of Big Little Lies is building to the same revelation about Jane's tragic past.