The hormone thing makes sense ..... after all, how can you train someone to do (or not do) something when they're asleep.
My son was dry during the night more or less immediately after being toilet trained when he was about 2.5.
My daughter though, despite being "advanced" (IMO anyway) in other areas, is almost 5 and I have only ever had 2 or 3 dry nights and none consecutive, which is what it would take before I risk no nappy.
I really feel for her because she gets terribly distressed by it. Obviously at her age she is well aware of what a nappy is and all the connotations with being a baby. I do wonder if she wees in it the minute she wakes up but then again when I've got up before her and woken her, the nappy's wet so I don't think it's that. She keeps saying "sorry" and "I can't help it" which is heartbreaking because I have never told her off nor criticised her.
I am interested however in the last posts from Litchick & Cookiemonstress who both had "success" simply by leaving the nappy off ...... as if the body can sense it's not "safe" to wee, and therefore doesn't ...... I've not been brave enough to do this yet but maybe I should bite the bullet or else I'll never know (and be prepared for possible bed changes in the middle of the night) ?