I went to school to learn how the mind works. Yet, in retrospect, it turns out that the mind was just a case study. I like to know how things work in general -- and how to repair them when they break. I dare not practice medicine without a license (as would be the case if I attempted to practice neurosurgery using my Dremel), but - per the Hippocratic Oath ("Above all, do no harm") - there is no harm in my diagnosing and fixing objects, be they simple or complex.
I am a psychologist who fixes Macs, especially (and things in general). I renovate furniture; I fix appliances, and generally tinker with gadgets.