Character Analysis
Manipulation Station
Memento is a movie full of shifty characters. A LSAT-level difficult game of "Would You Rather" would be "Would You Rather Meet (Memento character) or (Memento character) In A Dark Alley?"
But one of these nefarious schemers is even more nefarious, and even more scheming, than the rest: Natalie.
Teddy might be a bit ambiguous as to why he's manipulating Leonard, and how much of it is for his own good. Natalie, on the other hand, isn't pulling any punches when it comes to blatantly using Leonard for her designs.
Her manipulation, in fact, is so blatant that she straight up tells Leonard that she is going to use him. Why? Well, maybe she's just a big meanie…but we think there's more to it.
Could it be that she is seeking revenge on Leonard who, due to his clothes and car, obviously had something to do with her boyfriend's disappearance? Or maybe it's just about control? She feels helpless with the loss of Jimmy and with Jimmy associates breathing down her neck; she just wants some form of power to keep her sanity. It's not clear what the real reason is, but seeing as Natalie is dating and colluding with a drug dealer, we don't think she's going get her scruples in a twist over manipulating the "memory man."
It's also important that we realize her manipulation is not some spur of the moment decision she makes out of anger. Sure, it's true that she's frustrated with Leonard's inability to remember things, but notice what she does immediately after she comes home from work (if she really did go back to work): she hides all of the pens in the house from Leonard so he can't write down what she's about to tell him.
Her plan all along was to use him to get rid of Dodd, maybe even from the moment she invites him home. Why else would she offer to help the man dressed in her boyfriend's designer suit?
And when it comes to manipulation, Natalie is pretty dang excellent. She knows how to make Leonard mad, by talking bad about his wife—that bit about the STD was a low blow. Leonard hits her hard enough to hurt his hand but she just looks back with the most sadistic of smiles, knowing that she has won. And then she comes back inside and pulls off a very convincing acting job (it's almost like she's an actress and not a bartender).
From Bruising To Bonding
But, okay, here's the catch: the last time Leonard sees Natalie (and the first time we see her) she's acting very differently. She's almost helpful, which is weird for somebody who was Ms. Manipulation just two days ago.
So, the question is what, if anything, has changed? The simplest answer is: Dodd. Natalie needed to use Leonard to get rid of Dodd. Leonard beats Dodd up and runs him out of town and now Natalie is safe and doesn't need to use him.
Another answer is that nothing has changed. Natalie is still manipulative and is just using him to kill Teddy, who she knows is responsible for Jimmy's disappearance. The problem with this hypothesis is that Teddy tells us that Natalie doesn't know who he is and that nothing on his ID (where he's John Gamel), would indicate that he's Teddy. So unless Natalie is just trying to stay on Leonard's good side by helping him (and she has already demonstrated being nice to Leonard is not necessary for being "best friends… or even lovers") there's really no reason for her to help him out.
This brings us to the third, and seemingly most likely possibility, which is that Natalie has actually had a change of heart. When Leonard comes in upset about what he did to Dodd, Natalie is strangely consoling. Leonard is worked up about how his wife is "gone and the present is trivia, which I can scribble down as notes" while Natalie tries to get him to take his jacket off and relax. Then she sees the tattoos and she seems to understand him better as they both stare into the mirror and read what he's written on his own body. Natalie goes even further and identifies with his pain, saying that she lost someone too.
Is this an attempt to get recognition out of Leonard by showing him Jimmy and mentioning Teddy's name? Maybe, but maybe she really does feel connected to him. Maybe she regrets manipulating him—and is grateful for his help with Dodd and has somehow managed to go from being wicked to feeling sincere pity.
Ultimately, the mystery that is Natalie is just that: a mystery. We'll never really know, but we certainly wouldn't put another elaborate scheme past Natalie.