

If we don’t learn, then WTF are we doing with ourselves. The human existence is the pursuit of knowledge. The only depressing thing here, IMO, is the idea that living out a life as grazing cattle, concerned with nothing more than gorging oneself with the next meal is the only reason to live.
Comfortable? Sure. Self-actualized? Not a chance. There’s more to life than living out only the most basic biological needs.
6, 7, 8, 9 is the golden age of the series. I have a favourite among those four, but let’s leave it at that.