Polaroids (Symbol)
Polaroids are very important to Leonard pragmatically because they are his only way of preserving "memories." They represent information that he has already learned, but that he knows he will not be able to recall given his memory condition. They symbolize information and "facts" that are valuable to Leonard. Because he cannot make qualitative or interpretive realizations, he must rely on the Polaroids—symbols of knowledge and evidence that will help him achieve his goals.
Remember Sammy Jenkins (Motif)
Leonard has a tattoo on his hand that says, "Remember Sammy Jenkins." The tattoo is a reminder of Sammy, a man whom he investigated while he was an insurance investigator, who suffered from a memory condition. In Leonard's mind, Sammy represents the ways that his own memory condition can take a toll on those around him, and the fact that someone with his condition can be easily manipulated, and even disbelieved.
Tattoos (Symbol)
Leonard has tattoos all over his body in order to remind him of vital facts about his life. The permanence of the tattoos represents the fact that Leonard has his past written all over him, and that he is haunted by something that happened a while ago. They represent his seriousness about getting to the bottom of his wife's death.
His wife's book (Symbol)
At one point in the film, we see Leonard burning a worn paperback, along with other belongings. We then see flashbacks of his wife reading the book, and Leonard teasing her about the fact that she has read it many times. The book is a symbol of Leonard's memory of his wife, and perhaps of the ways he regrets not appreciating her more when they were together. As he burns the book, it symbolizes his desire to leave his wife's memory in the past, to move on and forget about his painful associations, the fact that he saw her assaulted.
The Phone (Motif)
In the black-and-white sections of the film, we see Leonard on the phone with someone, telling them all sorts of things about his past. Then, at another point, Leonard says that he cannot speak to anyone on the phone because he does better when he can look in someone's eyes. At one point, he is talking on the phone when he sees a note to himself that he ought not to use the phone. The phone in the motel room represents the fact that Leonard cannot trust anyone, and serves as a symbol for the way that Leonard is easily duped.
