What was the moment you Realised you werent as gifted as you thought you was?/ What was the moment you realised you couldnt get away with just using your intelligence and not doing anything else?

The question is phrased first of all to non mensans as mensans because Iam quite intrested in the contrast between the anwsers. Also besides of that Iam interested in how some of you dealt with the realisation of failing for X in life be it school work or social situations.