Forgive me for resurrecting this after so long just to add this, but...
The idea of "forgetting to fall" reminded me of when I was ~9-ish, and I discovered the concept of "dead weight". You know, how if you try to lift someone who is completely limp, they feel heavier than trying to lift someone who has gone rigid?
I experimented with my sister, trying to hoist her off the floor while she either helped, or didn't. It wasn't very scientific, but we were pretty sure that she was lighter when she stiffened up all of her muscles.
After that, I remember having dreams where I was able to hover, but I had to clench every muscle at the same time to become "bouyant" enough... and I woke up very, very sore.
Now, one question before I go try this new method... I wasn't clear on whether they ran UP the hill, or down...