Twilight, the gradual softening of the day into darkness, is surely the gentlest, most natural way to prepare for sleep. And yet it is a pleasure we deny ourselves with the switch on the bedside lamp. Even the guttering of a candle or the afterglow of a paraffin lantern is less abrupt. A couple of generations ago most country people went to bed when it was dark, at least in summertime. And so we miss the time of darkling shades in which our pupils dilate by slow degrees and dreams drift in as, wide-eyed, we enter the rook-black night.
-- Roger Deakin, Wildwood - A Journey Through Trees