Last September I lamented that the "lie-lay" distinction seems to be a lost cause. Joining it now, I think, are certain uses of "obsess" and "cliché." I've recently come across sentences like these in the writing of two forty-ish (I think) people, both very well educated, one of them a Ph.D:
I am obsessing about that movie.
That movie is so cliché.
And these instances are in books, not casual online commentaries, email, or text messages--books edited and published by reputable publishers, and so presumably approved by at least one competent editor. I despair.
If you don't notice anything wrong with these sentences, well, I guess you're on the right side of history for the moment. They make me wince, if not worse.
When you can't get something out of your head, you are not obsessing about it. It is doing the obsessing, not you. It is on the active side of that verb. It is obsessing you. You are obsessed by it.
Cliché is a noun, not an adjective. I'm not sure that it's even really a good thing to turn it into "clichéd," as in "That movie is so clichéd." I'm out of my grammatical depth in trying to analyze that, but it sounds better than "so cliché."
My authority for these judgments is my Webster's New Twentieth Century Dictionary (Unabridged), published in 1966. I guess it's a relic now, like me. It's falling apart, also like me. So cliché.