I recently had to watch this documentary for one of my classes, about the newspaper tycoon Charles Foster Kane, whose last word (allegedly) was "Rosebud". A big part of the documentary focuses on some reporters trying to figure out who or what Rosebud was. Personally, it sounds to me like the confused muttering of a senile old fool at Death's door, but I was curious if there any new theories about it?
Ah, yes, the well-known Welles documentary. Though it set tongues wagon and has inspired many curious people try to sort through the sledge of Kane's life in search of answers, I have to tell you that it's easy to luge yourself in the details. Far too many to make any real sense of, and in the end you'll have toboggan for the one that seems best to you. I've tried myself, and it was enough to sleigh me. You can easily go off the skids.
I honestly have no idea, and don't think we'll ever know.