Do you have a work journal? Consider starting a journal to track your daily activities and making note of important activities you encounter through the day. A journal will come in handy when you need to recall the events of a specific day.
No matter what you do give it a try if you are not journaling already.
(Note - this article was originally written by Drake Settsu and published on DrakeSettsu.BlogSpot.com in January 2014)
My journal, I take it everywhere with me at work. I put my meeting notes in there and notes from conversations. It really helps you out weeks latter when you are looking for information and can pick up your journal to retrieve it.
I have two actually, the public one that can be viewed by anyone in the project, and the private one where I really say what I think. I need to review both because the private one contains some key information on particularly stakeholders or issues in the project that one doesn't want to make public.