When I was a kid, I assumed that in the future things would get better and better until we were all driving flying cars and playing badminton with space aliens on top of 500-story buildings. Frankly, I kind of counted on this happening. But now I don't assume that we'll just keep going up anymore.
I think there's probably a point to which civilization will evolve, and then all the gas and water will run out and we'll spend the rest of eternity trying to get back to the awesome times when we had, you know, food to eat. I really hope I'm not alive when that turning point arrives, because it will be bad.