DS is 18 months and sleeps badly. He cries for about ten minutes every time we put him down, even if he was asleep when we put him in his crib. He wakes in the night, usually for an hour or so. He has never slept well, and has probably slept “through” (from bedtime at 7 to 6am) less than a dozen times. How normal is this? I look at people with more than one child and wonder how anyone manages.