Well, it is possible (and very easy) to forget dreams only seconds after waking up. I do it all the time. However, in my personal opinion, I don't think you are becoming lucid, waking up, then forgetting. When I WILD, I wake up a lot too. I think it is because we put so much effort and intention into it. Often, when you go to bed at night, you can set your intention to waking up at a spacific time in the morning. I think the waking after WILD thing is the similar principle. We are very focused on having a successful WILD, and I'm sure that helps wake us up also.