At the end of the day,there's probably little reason to pay attention to our dreams at all unless they keep us from slee

At the end of the day,there's probably little reason to pay attention to our dreams at all unless they keep us from sleeping of“we wake u in a panic,”Cartwright says Terrorism,economic uncertainties and general feelings of insecurity have increased people's anxiety.Those suffering from persistent nightmares should seek help from a therapist For the rest of us,the brain has its ways of working through bad feelings.Sleep-or rather dream-on（ it ）and you'll feel better in the morning.请问最后一句中的it指代的什么?