Ariadne: Why not?
Cobb: Because building a dream from your memory is the easiest way to lose your grasp on what's real and what is a dream.
Ariadne: Is that what happened to you?
Cobb: Hey listen to me. This has nothing to do with me. Understand?
Ariadne: Is that why you need me to build your dreams?
Ariadne, some what arrogantly, ignores some of Cobb's advice. The people in his subconscious start to attack her.