Every so often I stumble on something or someone that impresses me 
a great deal.

Because of my long involvement with communications (dating back to 
TubeElectronics), I have a real affinity for the gadgets of the
early years of comms.

In searching for data on various old gear, I arrived a series of
pages describing the German Enigma machine.  One of the links there
was to the site of Tatja van Vark, a Dutch lady of some (exemplary!)
accomplishment -- but with ''no formal education in electronics or ''
''mechanics. As she puts it: "I wanted to own a coding machine and ''
''now I do."''

This is the extreme of "self taught."  Clearly, learning and education
are not a one-to-one mapping.

Here are some links:

The Enigma machine that she built herself:
  http://www.tatjavanvark.nl/tvv1/tvvcm15s.jpg
  http://www.tatjavanvark.nl/tvv1/tvvcm17s.jpg

Other samples of her work can be seen at:
  http://www.tatjavanvark.nl