There is no such thing as an "awesome" world state, just a "more awesome" relation between two such states.

Sure. But "things are pretty awesome" is faster to say than "our current world is more awesome than most of the worlds that have existed in history".

The quote advocates pretending that we've already achieved perfection.

That's a valid interpretation of the quote, but not the only one. The way I read it, specifically the way it focused on the drinks and the word "complain", it wasn't so much saying that we should pretend that we've already achieve perfection but rather to keep in mind what's worth feeling upset over and what isn't. In other words, don't waste your time complaining about drinks to anyone who could hear, but instead focus your energies on something that you can actually change and which actually matters.