We absolutely were talking about self-driving cars in 2006, when no less a "major player" than the US Government had already been investing in this "science fiction" idea for two years, in the form of the DARPA Grand Challenge races. The 2007 race even required compliance with traffic laws in order to win. Google's autonomous vehicle program is a direct result of this project - that's why they hired Sebastian Thrun, whose team won the 2005 race.

I don't know how serious it was, but part of the initial PR about the Grand Challenge included the goal that it would enable the US military to convert some significant fraction of their fleet of ground vehicles to autonomous operation within ten years.

I do think the previous poster was overstating their case a little, but not so badly as you seem to believe.