That's the thing, I forget stuff. I usually remember to charge lights, but every now and then I don't. If a rear light happens to die on the way in, or front light is low, I just throw them on the USB cables and they're ready to go by the end of the day.

I also can't understand people who use flash modes in the dark. It's definitely not very safe. That's why I like the Night Pulse mode on the Cygolite, just a quick pulse but the light stays on at all times. If I can see the light on the ground, then I run it on that mode. Once the daylight gets bright enough to no longer see the light on the ground, I switch it to the Day Flash mode. That mode can last me up to a week in the summer when my whole commute is in daylight hours.