Rosebud in the film Citizen Kane has been used for various functions. First, it signifies the good times in the movie. Moreover, it idealizes the old days, whereby many people miss their childhood and the happy moments they experienced. Individuals can argue that the rosebud is used to symbolize the sacrifice made by Kane to grow up. Though Kane never mentions much about rosebud, the audience can learn that he faces pain when figuring out why he feels empty.
People have different childhood memories, with most of them being fascinating. Second, the rosebud shows that many people are genuinely happier in their childhood years than in their adult life. For instance, Kane is cheerful as a child getting ice from the streetcars and paying a nickel for it (Welles, 1941). However, those were fun times and really joyful moments that he had to give up to become an adult. Thus, the rosebud has been used to show the different aspects of human life.
Reference
Welles, O. (1941). Citizen Kane [Film]. Mercury Productions.