That is why I always assume I will end my ride after dark. I always bring my lights no matter when I start my ride. Not really a big deal. You never know what can happen on a ride. Maybe you get mechanical trouble that takes a long time to fix. Maybe you end up walking. Maybe you just decide to go for a longer ride or have side trips or go to a restaurant, etc... Maybe there is a wicked storm that comes on suddenly and you need lights at noon because it is so dark.