My basic electronics training kept me going through my years on submarines (I let the electrician's mates deal with the voltage/current/phasing my equipment used.) In my civilian career I had to learn about three phase five wire wye supplies for the equipment we worked on, and, before I left that field, I was traveling around the country doing power quality surveys at hospitals where our systems were installed. I never worried about sngle phase elect. much (though I did bring some of our test equipment home to scope out the house I was leasing back then (two wire, the only ground was at the service disconnect/panel) --- Since I learned 3 phase, my somewhat autistic mind handles it better when I think of my household single phase as two phase, 180 degrees out .... (edited to remove the typos I caught --- I don't like this laptop keyboard --- not forgiving at all)