Ok, that’s better. I can handle 7 as a “starting” point for discussion of a semi-fixed cultural acclimation. [I don’t think “childhood amnesia” is fully correct – this is graph of average memory counts – you _can_ improve your recall of earlier events as memory is something one is constantly working on – it is not static]
In any event, whatever we call a culture – you can call a common black experience in America a culture just as you can a particular Indian religious culture, or being raised in the Midwest US or whatever – is learned through repeated exposure over long periods of time.
To say that one can have “only one” – I mean ,you can argue that each person’s is UNIQUE in a sense – that is like any lived experience I suppose – but to say that one cannot have a duality of culture still makes no sense as your learned behaviors and responses change from your environment; your patterns of thinking change when you’re with friends or your mother or your dog — each forms its own little “bubble world” you work within.
Culture is a vague broad term that can cover a lot of things and is hardly coalesced enough to be considered as having any kind of hard boundaries, unless one’s cultural is media and experience isolated; you are GOING to be exposed to multiple cultures except in odd cases.