Steam
There does seem to be an almost universal internet concensus that, across all males of any ethnicity, the average erect penile size range is between 12.8 cm and 15.3 cm (Google will convert that for you): at best historically I might have claimed 13.7 cm and about 13.9 girth, though at best wasn't about to try to measure accurately. So perhaps the reality question could be rephrased as how familiar are people of any gender with the internet average?