Two more factors come to mind as we continue our observations for the month of July - three, actually... physical fatigue, mental fatigue and amount of sleep.
I have noticed that my recall has suddenly returned to normal. I am using no supplements at all right now... taking a break from them... but I am working longer ours than normal and sleeping less. Mental fatigue is low, but I'm physically pretty whacked by the time I get to bed at night, and sleeping 7 hours or so with no naps.