What You Remember != What is Important

People tend to assess the relative importance of issues by the ease with which they are retrieved from memory—and this is largely determined by the extent of coverage in the media. (Location 126)

Ties into the primacy effect:

The primacy effect is a cognitive bias and refers to an individual's tendency to better remember the first piece of information they encounter than the information they receive later on.

The things we remember we are more likely to rate as "important". Marketers and YouTubers understand this by putting the hook within the first 10% of the content.