Thinking About Thought

From the home page:

'Imagine that 'sight' is a limited resource. It is made available to each of us for just one year between our twenty-first and twenty-second birthdays. All of our existence up to the age of twenty-one is spent in (what sighted people imagine as) darkness and we will return to that same darkness forever on reaching the age of twenty-two. On returning to the darkness we will remember nothing of what we have seen. Importantly, all these facts are known to us.'