It is the difference between passion and education. Someone who passionate about technology is really interested in all the bits and crevices, someone who is simply learned about technology classifies knowledge into 'useful' and 'not useful' parts. A common example is 'car people' who go through and re-design the fuel injectors for their car. It isn't "required" but they really like everything about all the pieces. So they persevere to understand it all.