Advanced technology hidden from us ?

Over the years I have heared that governments all around the world secretly use more advanced technologies than the ones that we use during our modern day and everytime they discover a new piece of technology, the old one is passed down to us. To me that makes logical sense simply because each government will:

a) Want their own militaries ahead of other militaries around the world.

b) Give them the feeling of superiority and safety.

I would like to ask you all if this is simply a rumor that is passed from person to person, or if it is real. Because if so, imagine the communications, weaponry, defense and transport that they use.

so far from what i've seen...they use the same stuff as we do...just amped slightly....the computers i work with run linux....only the office computers are running windows....the office computers suck chicken butt...however...my gaming computer is about the same power as some of the equipment i work on....