BasketCase
Username sez it all
Title sez it all.
For me, the runner-up might be that case in the "Who's Your Nemesis" thread, when the Persians sneak-attacked one of my cities, destroying an empty army and toasting my Military Academy....
....but my real Dumb Thing (in the same game) was reaching Modern Age and going straight for modern armor. I finish researching Synthetic Fibers. I go to the map to see where the aluminum is, to connect it up to my empire so I can build tanks..............
Surprise! NO aluminum ANYWHERE. I spend half an hour staring at the map, unable to believe that my vast empire doesn't have any aluminum in it, wondering how to approach the endgame now that my strategy has been disabled.
Then I realize--I can't SEE where the aluminum is, because I HAVEN'T RESEARCHED ROCKETRY YET!
Duhhhh!
For me, the runner-up might be that case in the "Who's Your Nemesis" thread, when the Persians sneak-attacked one of my cities, destroying an empty army and toasting my Military Academy....
....but my real Dumb Thing (in the same game) was reaching Modern Age and going straight for modern armor. I finish researching Synthetic Fibers. I go to the map to see where the aluminum is, to connect it up to my empire so I can build tanks..............

Surprise! NO aluminum ANYWHERE. I spend half an hour staring at the map, unable to believe that my vast empire doesn't have any aluminum in it, wondering how to approach the endgame now that my strategy has been disabled.
Then I realize--I can't SEE where the aluminum is, because I HAVEN'T RESEARCHED ROCKETRY YET!
Duhhhh!