But I still wonder how it was possible, in those graceless years of transition, long ago, that men did not see whither they were
going, and went on, in blindness and cowardice, to their fate. I wonder, for it is hard for me to conceive how men who knew the word “I,” could give it up and not know what they lost. Based on the excerpt, it can be inferred that the narrator believes that
I think the narrator believes that the men he is talking about lacked vision to anticipate future problems and courageously deal with the consequences ie they did not actively or proactively deal with life but on the contrary allowed themselves to be victims of circumstance. Re the word "I" I think he means that they did not realize the power they had to change the course of events.