The GPS. Seems we spend more time dicussing it than flying!
It is very satisfying to navigate without it and when taught to navigate properly, there is no reason to bust airspace in good VFR weather. As someone who uses it everyday, I can't knock GPS, but I do find it nice to do it the old fashioned way when given the opportunity.
But one or two have mentioned airspace and the amount of people using it. Granted in CAS there is much more traffic. But OCAS (and I am thinking ooop north here) there seems to be far less military traffic. There are also fewer military aerodromes than there were say 20 odd years ago. Is navigation really that much harder than it was and is there really that much more hardware to avoid?