Everything is relative to ones "own little world"
The universe is supposedly hurtling along at umpteen KPH
Our solar system is also zooming along
the earth is zipping around the sun
In our little airplane, putt putting along in the sky - "our little world" is the moving mass of air we are in -
If we measure our aircraft speed against anything else - it all takes on a new vantage point.
My favorite hot air balloon story is still the one about the guy in a balloon who called down to the ground and asked where he was -
200 ft up in a balloon -obvious answer - but of no value to the guy in the balloon.