So it turns out that men tend to think that their manhood is larger than it actually is.
According to some research undertaken by a German tech blogger called Lukas - which he published on Reddit under the name JEMUS42 - men really have very little clue about the exact size of their package.
Lukas looked at data from all over the world, and while the size of penises differed - overestimating the size of their schlong was one thing the men all had in common.
To help us all get to, er, grips with the study, Lukas compiled the graph, above. The orange measurements show how big the men think they are (flacid on the left, erect on the right), and the green data shows their true measurements. As you can see - men overestimated their size by around an inch each time.
But what we really want to know is... no, not why did Lukas undertook this research in his spare time - apparently he just REALLY likes data! But does it really matter if men say they're bigger than they are?