The true meaning of All Hallow's Eve/Samhain may be lost in the past, but there's nothing wrong with celebrating it the way we do now. I love going to Halloween parties and seeing the latest costumes. There's something magical when you meet someone for the first time in costume. All the barriers are down. Just like the ones between the two worlds. I've had some of those magical encounters on Halloween.
Anything is possible on a night when monsters, humans, and all manners of creatures mingle.