Speaking as someone who believed all the hype about having fully autonomous cars by 2020, I think the truth is that it is orders of magnitude harder than we thought it was and that we are orders of magnitude less capable than we thought we were.
Maybe a good interview question for experienced developers should be "tell us about a time when you attempted something in software and failed at it." In my case it was being given a 10 or 20 KLOC C server that had memory leaks all over and segfaults all over the place (written by a friend) and told to make it prod ready.
That's a rough one. Mine was fixing some physics/flight aerodynamics software that had been generated by a Fortran-to-C compiler (e.g., http://www.netlib.org/f2c/). It was in inscrutable mess and couple-years-out-of-academic-physics-turned-SE me thought I'd be able to do it easily since I had so much Fortran and C experience. I failed quite hard at that.
