Who are you?!
We had a conversation and I have introduced myself. This is how I know your name. If I revert to ask how are you and you reply “Nice. Who are you?” that is grammatically, semantics-wise and logically incorrect. Maybe you are fine, you are definitely not nice, mainly because you’re definitely not that much into me or you’re amnesic, confused or rude. Either way I won’t dignify you with another conversation attempt. Apart from this blog entry that is.
