Whats average? Too lazy to discuss this. I will say that because are too many cultural barriers, it is impossible to define what the average is as well as what normal is. In addition, even of there was common sense these cultural barriers wpuld cause different ways of thought/perception of whatever the matter was.
Average can apply to everyone living on the planet. For example, the average human being eats 3 meals a day. That would be an average taken from the pool of humans who live on Earth.
Saying too much culture makes 0 sense. Since defining average can be broad enough to cover all cultures or small enough to only focus on one. The word by no means is limited. It's just a mathematical term to show the most common result out of a pool of data.
You never provided an example. Sure there may be an average on mutliple levels but there are still cultral barriers. There are still people who eat 5 meals a day and dont view 3 as normal to them, and the same can be apllied ti those that petcieve the idea of 5 meals a day.
While am repearing what you just said you are just supoorting my intial claum on common sense nkt existing due to cultral barriers