Clearly, I'm a writer, not a photographer. But the above stack of notebooks is the end result of my journaling career. I kept a journal from Christmas, 2000 to shortly after I graduated college in spring of 2005. Then I stopped.
There are a lot of things I wish I'd journaled. I traveled extensively in high school, and I wish I had a more detailed record of scrambling up the cut stones of a pyramid (which isn't legal in Egypt, by the way), eating pierogi with a former member of the Polish resistance during WW2, and swimming with dolphins in the Bahamas, but I wasn't journaling then. Since graduating college, I wish I managed to keep a journal about being a young platoon commander in the Marine Corps, marrying my wonderful MJ, and serving in Iraq. Somewhere along the line, though, I became too busy with other priorities to keep a record of what was happening!
But I've also read the journaling is highly optional for writers. The strong memories, after all, the ones that can truly inspire your writing, will cling to you anyway. The dull moments can fade away and what you really NEED to write about will remain.
I'm not sure I believe that, but I have to admit, I use my journals for nostalgia purposes. Their primary purpose in my writing is to connect me to emotions, not moments -- I can flip open one of my novels and relive all the highs and lows of being seventeen, nineteen, twenty. I don't go there for details or inspiration.
How about you? Do you keep a journal, and if so, how does it fit into the rest of your writing life?