Do they forget everything at the end of Lion, The Witch and The Wardrobe?

I was a bit confused, at the end of the movie Susan, Peter, Edmund, and Lucy where all grown up. Then when the found the light post, they stumbled back into "Spare-oom". There they find the professor. Did they forget all about what happened in narnia? And if they go back, are the people doubtful that it is really them? Or is that in the next movie? :O Thank you to anyone who answers