Amidst feelings of depression and suicidal thoughts, Leonard writes himself letters from the future. Herr Silverman says, “Write the letters from the future, Leonard. Those people want to meet you. Your life is going to get so much better. I promise you that. Just hold on as best you can—and believe in the future” (122). This hope helps carry Leonard through his darkest moments and propels him toward fulfillment. 

At the novel’s opening, Leonard’s circumstances tell him that he is alone and doomed to live a miserable life. As Leonard gives gifts to Walt, Baback, Herr Silverman, and Lauren, he wishes these allies would come to his rescue. He searches for reasons to, as he writes to himself in the letters, “Hold on” (77). During his final day on earth, Leonard looks one last time for signs of hope. 

For years, Leonard has also looked for hope as he followed commuters to Philadelphia. He wonders why people with so much opportunity for joy experience so little of it. He tells the woman who cries on the train, “I want to believe that happiness might at least be possible later on in life for people prone to sadness” (55).