I think the secret to WILD is hitting that sweet spot between being too aware to actually fall asleep and being too sleepy to actually stay aware: in the sweet spot one is sleepy enough and aware enough, but it is so easy to miss WILDing because of leaning one way or the other. Most of my WILD attempts end with either my staying awake or my falling asleep unaware, but I shall continue trying because I did it once and I know I can do it again.