Thank you, emsr2d2:
I always think that "can not" and "cannot" have the same meaning. Now, it is clear.You can go = You are able to/are permitted to go there.
You cannot go = You are prohibited from going to the unspecified place.
You can not go = You are permitted to make the decision to not travel to the unspecified place.
BTW, Congratulations, Moderator emsr2d2 !
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.