Recently, there was an article put out by the American Association of Notaries entitled "Why are Notary Journal Entires Important?". It talks about the use of journal entries that some notaries are required to do and some are recommended to do. Whether it is required all depends on the laws in the state in which you are a notary.
In my opinion, these entries are not only important but vital and should be mandatory. The article writer mentions that she takes out her journal as the first thing she does when notarizing a document for a signer. It reminds her the steps to take and what is required by her state to do a notary as those things are notated in her journal entry.
In California where I am a notary, a journal is a requirement. I also use it to remind me of what is needed, when to get the information and to make sure all is correct with the signer and the signers ID. There is one signer for whom I have done several notaries. Even though we are friendly with each other having worked together so many times, I am always ask for his ID and get a thumbprint for the journal entry. I get a thumbprint even though it is not required by law since it is another method of making sure I have gotten the same person's signature each time I have notarized a document for him. It protects him and me in the notarization process. I can't imagine why any state doesn't require journal entries to be made for each notarization. It's part of the process I use to protect against fraud and to make sure that the process is done correctly each and every time.