Unbelievable. I've read through this thread and it's just brought everything back.
When I was small I used to do this all the time. And I'm sure not only at night, something had to be 'right' but I remember just gently going down, watching every step under my feet, this kind of rushing feeling/noise in my head as I went, this really strange feeling that was so exciting. It was a confidence, thing, for as long as I believed I could do it, I could. It was so easy, you'd just step off and down you go, no crunch at the bottom, so perfectly in control all the way.
In the earlier days I was somewhere between thinking it was something so normal I didn't have to think about and being a bit worried, like I couldn't rationalise it in my head so I used to agonise about telling my mum about it. I think eventually I did but I didn't get an answer/the answer I wanted so it still concerned me a bit.
As I got older it became less regular until it was like I never could - despite still vividly remembering what I could do I just knew that if I tried to do it I'd fall. Confidence thing I guess. But it was gone.
I'm 100% certain it wasn't a dream, I was conscious and it happened.