A single person can add to but not change a society. If the society isn't advanced enough or human enough or sober enough even the most decent and nice idea you bring to them can be poison or gets rejected. Count the civilisations crusaders of all types have ruined. Count the societies that got derelict due to imported things that were so ill and bad like foreign religions for example. I think 2000 years ago I would shut the fuck up and try not to ruin their life.