On a related note, when it comes to types I find very odd the persistent notion that a statically typed language means it's vital that you get the types right a

On a related note, when it comes to types I find very odd the persistent notion that a statically typed language means it's vital that you get the types right at the outset. Quite the contrary, as we build anything, we necessarily pick some way of organizing our code and our data. When we inevitably discover that we were horribly wrong, it is tremendously valuable to be told more about what needs to change in concert as we reorganize.