Why is it remarkable that our brains process input from our 5 senses differently from delusions that originated in our heads?
Just as an interesting side point, I was listening to Science Friday on NPR (National Public Radio in the US) and they had on a biologist who pointed out what we've traditionally thought of as our five senses turns out to be way more.
http://www.bbc.com/future/story/20141118-how-many-senses-do-you-have