One interesting finding here is that we have many more associations to Mondays and Fridays because these two occur much more frequently in natural language, for example there are many pop songs that use Monday and Friday, but very rarely do any songs use midweek days.

I wonder why the first conclusion drawn here is, that Monday/Friday occurring in "natural language" more often is the cause for these days being more recognizable, instead of both of these facts - them being memorable and talked about often - being a natural result of them representing beginning and end of the average working week. I feel like this would be the more logical conclusion.