Especially when you don't like your lights too bright.....I've got a set of Ay-Ups, and although they are really good, my buddy has an exposure six pack (or similar), that turns night to day! Silly bright, IMHO.....
I've still got my old Light & Motion HID NiMH lights. Not as techy and long-lasting as more modern LED - li-ion setups, but still a great beam pattern and good weatherproofing. They must be nearly 10 years old now.
That can make it bloody hard work. Night-riding when you can't see the trails is even more ridiculous :-)