I'm sorry, I didn't notice it was a commuting-related thread.

About ten years ago I was working evenings, which means I got off at 11pm, and rode home then. Most of the ride was on a bike trail, and there was limited traffic at that time otherwise. I was set up pretty good with blinkie lights and reflective stuff all over.
One night, I was riding the usual route on the trail, but in a seriously dark area, with no street lights and lots of trees to block whatever ambient or moonlight there was. Well, I heard some noise, but it seemed far ahead of me, so I paid no mind to it. After about thirty seconds, whammo! Two guys on bikes coming the other direction and I meet head on. Boy, was I pissed! I really gave them the whatfor about not having lights and being unsafe at night. Get a clue, and all that. After apologizing, one of them poited out that my blinkie lights weren't working either, and there wasn't enough light to make the reflective stuff useful. Humble pie for me, because I had never turned my blinkie lights on. If I had, there wouldn't have been the problem!