Magic Coincidental Tuesday
I was checking out the very neat Google History feature and discovered that I do far more searches on Tuesday. In fact, it looks like a graceful curve that peaks each week on Tuesdays.
Your brain looks for coincidences wherever it can find them. That's how we make sense of things. Even though the chart seems to be clearly non-random, I can guarantee that there are no external factors at work here. It's a coincidence. Short version: just because a graph looks good doesn't mean it's true.