There's an old saying in the Artificial Intelligence community: once software starts working people stop calling it AI. You could make the argument that the opposite has taken place during the last 6 years of the neural network renaissance with Machine Learning researchers returning to the term AI as the old stigma of exaggerated hype wears off. However, it does point to an interesting guideline for technological maturity: it's mature when you stop noticing it. That's why the old Palm Pilots were a conversation piece but modern smartphones go completely unnoticed. One particularly powerful implementation of Deep Learning is in the proliferation of Voice assistants.