my 2.5yrs DS will often go to sleep v quickly (within 10mins of going to bed - usually takes at least 30mins). Almost invariably when he goes to sleep this quickly he will wake almost exactly an hour later, crying, and quite difficult to settle back to sleep (he seems v sad).
I'm not sure there's anything we can do to avoid this (it tends to happen when he just gets v tired in the day, sometimes we just can't get him to bed early enough).
I was wondering if you had any ideas why it happens, so we can better understand it. Also, is it a common behaviour?