This was my first time trying to grasp the work. The hardest thing to understand for me was its structure. It modulates from key to key, isn't unified by any particular theme- only suggestions of past "utterances" and passionate, ascending sequences that seem to be abandoned later. Then there is a passionate outburst at the end- but where did it come from? I don't know. Before, Chopin was just being his "reflective," "lyrical" self. There are many beautiful moments but I don't understand the logic that connects each movement.
I tried doing a structural analysis... many of the different sections and themes are intertwined, sharing themes and motivical ideas, so I don't think there is a definitive way of doing it, however here is my take:
*EXPOSITION* (Home key)
INTRO
1-8 Fantasy intro, searching for the key.
9-22 Branching out from the intro, main theme appears, still searching
MAIN THEME
22-50 Main theme in home key
51-65 Episode woven out of the main theme leading to
*DEVELOPMENT* (Modulating, important themes passing through keys related to the home key)
MODULATION
66-92 Episode with a new idea, starting in home key and modulating until it reaches
MAIN THEME
92-115 Main theme in the dominant key, then modulating to
EPISODE
116-147 New declamatory melody, starting in B flat (the dominant of the dominant) and modulating to
*MIDDLE SECTION* (Mediant key)
SECOND THEME
148-181 Now in B major, a new theme is introduced.
EPISODE
182-205 Another declamatory section, starting in the relative minor of the second theme, the rhythm of the melody being close to identical to the earlier declamatory section in B flat
206-213 Reminiscenze of the second theme in B major, ending the section.
*RECAPITULATION* (Home key)
INTRO
214-215 Fantasy Intro returns, modulating from B major to
216-225 The declamatory theme, starting in the relative minor of the home key (f minor).
226-241 Buildup to the return of
MAIN THEME
242-253 Main theme returns in home key
SECOND THEME
254-267 Second theme also in home key, now in dotted rhythms.
CODA
268-288 Second theme explodes one last time and dies down into the ending of the piece.