Symbolism, Imagery, Allegory
There's a Hole in the World
No, we're not talking about the Louis-Sachar-novel-turned-Shia-LeBeouf-movie, we're talking about the way Rachel and Megan feel like they have holes in themselves and the different ways they each try to fill them.
Rachel's hole is self-imposed in a way—the "black hole in [her] timeline" (7.212) is a result of her blackouts. She wants to fill it in by filling in her memories and reclaiming the moments in her life that she has lost. At first she says she's "too afraid to venture into that darkness" (9.32), but she eventually does and benefits from it.
Megan, on the other hand, has holes from abandonment. Her brother died, her baby died, and her first boyfriend left her forever. Megan believes that "the holes in your life are permanent" (8.13), and her solution is to have affairs to occupy her time. Thing is, if Megan's holes are permanent, it's because her solutions are temporary. Rachel's hole ends up being temporary because she finds a way to permanently fill in those memories while figuring out how to stop building the hole (a.k.a. get sober). Whose strategy works better? We're going with Rachel since she tries to get to the root of her problem instead of settling for quick fixes.