Although we have learned that Utterson is one of Jekyll’s oldest friends, we now discover that he has never been to the Doctor’s garden. What might this suggest about Jekyll’s nature? What does it show about his friendship with Utterson?

This may suggest that Jekyll is secretive about certain things. Though they are very close, this part of Jekyll's life is completely hidden from Utterson, which is fairly strange. The author implies that Jekyll chooses not to reveal very specific aspects of his life for whatever reason. The author also hints that their friendship does not run as deep as it may seem. It is not as strong as it could be because Jekyll chooses to shield himself partially from Utterson.