It's interesting this xkcd seems to be making the point that complaining about the increase in pace from the previous generation is as old as time itself. This conclusion is plausible, however I would be interested to hear opinions from earlier than the 1800s. If you consider the past 300 years in the span of human evolution, it's miniscule. On that timeline the 1800s seem much more closely related to modern day. My point being that decreasing attention span could still be considered a relatively 'recent' phenomenon.