Yes you do, since..
Michael Caine has stated that his character is never in any of the dreams, and Cobb always has his wedding ring on when dreaming.
OnT:
Blue Valentine had a sad ending simply because things doesn't sort themself out.
Requiem For a Dream (Ending crushed my feelings. I literally stared into the screen for two minutes trying to sort my mind.)
American Psycho (Wait..what? Did he or did he not kill?)
Shutter Island (Simple.)
and..
Memento too.
I know that I feel kinda mainstream naming these movies but these are the only ones on my mind at the moment.