Adrienne Rich's poem, "Amnesia" uses references to the 1941 movie, Citizen Kane to provide focus for her poem.
Citizen Kane is about a once-powerful and rich man who dies, clutching a snow-globe with a likeness of his home, whispering the word "Rosebud." After his death—and told in flashbacks—a newsreel reporter searches to find the meaning of "Rosebud," and for the real man behind the public façade. We learn that at a young age, Kane's poverty-ridden parents suddenly come into enormous wealth, and his mother ships him off to be raised by Thatcher, her banker. This seems to have been a devastating event in Kane's young life: losing his innocence in being separated from family, and later, losing his idealism. (At one time he wanted to use his power and wealth to help those who had no public voice.)
Ultimately locked in the grip of wealth and power, Kane loses his dreams, his second wife (his true love), his reputation, and all he owns. His death, which begins the film, brings "Rosebud" to the forefront of the viewer's mind. Not until the end of the movie does the audience learn that it is the name that was painted on his sled—the sled he was on when Thatcher came to take him away. This is central to Kane's inner-self: his loss of connection to his family— those he loved.
Note now the beginning of the poem: "I almost trust myself to know…" She does not quite trust herself yet. She mentions the movie scene with the snow-globe. She notes the "mother handing over her son." "The earliest American dream" may refer to that mother wanting for her son what she never had. It is, however, the mother's dream, not the son's. Rich refers to the old "black-and-white" movie that shows "incandescent" snowflakes—bright, glowing, larger than life—reaching into the "cold blur" of the past. Two things to note: the "black-and-white" may allude to the idea of youth—these two colors being associated with the absolutes...when one is young, and before "greys" make life so difficult. Second, the past is "cold," not warm and welcoming.
"But first" indicates Rich's shift in focus. The "picture of the past" could refer to movie or a snapshot, not in color (an old picture). The picture—simple as it is—Rich compares to the "pitiless…deed" of "the putting-away of a childish thing," alluding to the Bible verse, I Corinthians 13:11: that speaks of becoming a man. Rich must carry pain about this "putting-away" because she associates it with leaving:
Becoming a man means leaving
someone, or something—
The leaving at the poem's end echoes Kane's mother sending him away in the movie. The snow mentioned in the poem at this point is blocking out what is left behind—it would seem that Rich changes the perspective from Kane looking into the globe remembering the loss of his home and family (and perhaps himself), trying to see his past through the snow…to the speaker, the one who is left behind—looking out of the globe, through the same snow, as she watches the "becoming-a-man" leave her. The snow of the globe blots out the sight of the one who looks back on leaving, as well as it diminishes the sight of the one who is left behind when the other leaves.
The "picture of the past" does not indicate when this happened, but it would seem that Rich has not forgotten: her amnesia is not quite complete. And if "we're getting to the scene," the speaker may be remembering the first parting, and looking now to another similar parting, where she is once again left behind.