It isn't so much that the LSD "opens" anything, it's more of a tool used by the subconscious to bring to the forefront certain pieces of information that are already there. Think of it as tying off loose ends to connect related pieces of information. The drugs themselves do not bring anything "new" into the brain, but instead just allow for greater access to what is already there. The reason these changes in thinking are so long-lasting (and even life-long in some cases) is due to an alteration of a physical structure of the brain. It's as if the brain is an encrypted computer file, and the drug sets off a series of subroutines that not only allows access to one section of it, but changes the framework to allow greater access in the future.