My GPS has a moving topo map with track recording... In other words, I can follow my rabbit trail exactly (within reason and error correction of the GPS) back to where I started.
That being said, I still don't leave home without my common sense... batteries have a life and often fail at most inopportune times... I have had the software freeze up on the GPS in the middle of a trip... You could drop it in the lake/river...
Sure don't want to place all of your eggs in one basket so to say