Just a few thoughts on this famous piece:
There are words in German that can't be translated precisely.
One of these is "Zufriedenheit" which, in the romantic language, means something like "being satisfied", and it has more meanings. Another one is "Behaglichkeit" (comfortableness, cozyness), this one can have an eminently positive sense. But both of these may also signify a sort of "bourgeois" state of mind, in which people are just seemingly happy, but after all it's like an illusion. They don't want to see the abysmal aspects of the world.
A lot of people see only "Behaglichkeit" and "Zufriedenheit" in Schumann's Träumerei. And of course it is actually there. But there is much more in this piece. The uncertainty, the doubt, Schumann's love for irony (Heine!), the abysmal sadness. One of the "saddest" pieces written in a major key, to me.
Rachmaninoff talked about "the point" that every piece (or even concert program) leads to, and about a Scriabin recital he gave, in which, as he frustratedly thought, he had "missed the point" while all the listeners and critics were full of praise for him!
To me, the "point" of this piece, the turning point, the "climax" lies in m. 16, there is a short moment where we lose the ground...I can't explain it better at the moment. It has something to do with the A7 and it's resolution to the parallel key D minor. That's why this ritardando (like so often in Schumann without a following "a tempo") appears, this happens not only because of a convention. And then we get back to "Zufriedenheit" but it's not really "Zufriedenheit", it's rather, like so many moments in "Kinderszenen", a walk above an abyss...
This "abyss" is actually not only something negative. It has many different aspects. Schumann knows it's positive and negative aspects and doesn't get tired of bespeaking it, like in "Kind im Einschlummern"...a glimpse of a higher reality and another glimpse, one of a "lower" reality.
So, as I see it, Schumann plays with the "bourgeois" clichés of "Zufriedenheit" and "Behaglichkeit" only to lead them ad absurdum, not in a revolutionary or aggressive manner but in a subtle, tender one....