If Life Begins At Forty, Why Does Schooling Begin At Three?

My three year old started school at the beginning of September and is absolutely loving it.  The school year here in the UK is rather foreign to my wife and I given that we always had an academic year which started in January and ended in December; the norm for any school-going child growing up in South Africa.  September to July still feels very strange to us; what's all this starting in the middle of the calender year stuff all about?  Whilst this is something which doesn't take that much getting used to, the prospect of a three-year-old attending school, does; albeit only nursery school.  There is something alien about expecting children as young as three to follow a timetabled, structured day.  To be fair, my daughter gets to play most of the day away and has made loads of friends (the sudden influx of birthday party invitations is testament to that), but I still wonder if the "homework" tasks she receives are that necessary.  Yes I want my child to be challenged cognitively, but is it worth me sitting down with her flashing shapes and colours in her face so that she can get better at these "necessities"? As a Christian, I don't believe in many of the aspects which the Theory of Evolution brings to the religious table, but what I can take from this theory, is the idea that, from an evolutionary psychological perspective, we as humans are not genetically wired to sit still and pay attention for long period of time at age three.  Am I questioning the school my daughter attends?  Absolutely not!  We are blessed beyond words to send her to such a fine academic institution.  Am I questioning the government's insistence on children starting school so young?  Absolutely. Do I think this will have some form of irreversible effect on them in later adult life?  Don't be silly...maybe it is just that I don't want my little one to grow up too soon.