Put your flippin' lights on!!

Be warned - rant incoming - look away now if of a nervous disposition!

We drove from Cornwall up to Wiltshire this aternoon - A30/M5/M4 - in absolutely filthy conditions mist, heavy rain lots of surface sray etc etc. I was absolutely staggered by the number of vehicles being driven with no lights on at all? Why do they do it? Do they think they're saving battery power? have they got an Auto light function and don't realise they're allowed to override it? Who knows, but IMHO they are idiots and a danger to other road users! What do others think?

OK - rant over - stand easy! - as you were! - carry on etc!