Rosebud

 "One day, back in 1896, I was crossing over to Jersey on the ferry, and as we pulled out, there was another ferry pulling in, and on it there was a girl waiting to get off. A white dress she had on. She was carrying a white parasol. I only saw her for one second. She didn't see me at all, but I'll bet a month hasn't gone by since that I haven't thought of that girl."

Herman J. Mankiewicz & Orson Welles - Citizen Kane