This is where most applications of NLP struggle, and not just chatbots. Any system or application that relies upon a machine’s ability to parse human speech is likely to struggle with the complexities inherent in elements of speech such as metaphors and similes. Despite these considerable limitations, chatbots are becoming increasingly sophisticated, responsive, and more “natural.”
Pop-culture references to Skynet and a forthcoming “war against the machines” are perhaps a little too common in articles about AI (including this one and Larry’s post about Google’s RankBrain tech), but they do raise somewhat uncomfortable questions about the unexpected side of developing increasingly sophisticated AI constructs – including seemingly harmless chatbots.
Chatting with a bot should be like talking to a human that knows everything. If you're using a bot to change an airline reservation, the bot should know if you have an unused credit on your account and whether you typically pick the aisle or window seat. Artificial intelligence will continue to radically shape this front, but a bot should connect with your current systems so a shared contact record can drive personalization.