I experienced the same thing last fall, when I commuted home from the train station, at 8:20 PM, about the same distance as you. I had a blinkie on the back of my bike and one clipped on to the top of my screamingly reflective safety vest. A flashing band on my left leg and arm, too. For the front I had had a fairly good mini-Newt on flashing mode and the first time, I also had my headlamp on my helmet.
Well, once I got out of Concord center, I could not see at all! The streetlights are few and far between and they were all on the other side of the road. That made a huge difference. I wore my clear lenses in my sunglasses and they also fogged.
Next time I got another front light to add to the mini-Newt. It was more of a light to see, rather than "be seen", as the headlamp wasn't bright enough. It was an improvement, until the night it started raining, apparently only along the path I was riding...
I haven't done any night rides since then, but you are right, it puts everything in a different perspective.