Hello again,Imagine where humanity would be today if the ancient Greeks had continued on their path of enlightenment (from which Western Civilization had its start).
I suspect all intelligent civilizations had their ups and downs and rocky starts.
Aside from that, life requires at least a couple of generations of stars (from formation thru supernova) to create the right mix of heavy matter from which to develop. This narrows the window a bit.
Well strictly speaking, it is certainly clear we are not the dumbest. Smaller brain animals right here are Earth are considered dumber. That only leaves room for the smarter. When I say smarter, I mean more technologically advanced. Of course there are so many "gotchas" because of all the destructive mechanisms in the universe such as supernovae. If we don't get time to progress, our technological progress comes to a grinding halt.
This makes it incredibly hard to guess what the heck is out there, if anything. Maybe we assume "smarter" because we are not as interested in "dumber" because we have plenty of that right here. "Dumber" would still make a difference (first proof of alien life) but "smarter" could be an even more incredible discovery.
It seems we are always in the midst of finding something more incredible than what we have so far. Newton's apple to Einstein's train, and our Earth at the center to nobody's at the center.
It does seem though that the further we go the harder it is to make new improvements. It's only when somebody stumbles onto something really amazing that it changes everything.