I don't disagree with any of this but

> "Why in the hell would you fork then load, instead of load then fork?"

In python it often seems to make little difference. The continual refcount incrementing and decrementing sooner or later touches most everything and causes the copy to happen whether you're mutating an object or not.

I've had some broad thoughts about how one would give cpython the ability to "turn off" gc and refcounting for some "forever" objects which you know you're never going to want to free, but it wouldn't be pretty as it would require segregating these objects into their own arenas to prevent neighbour writes dirtying the whole page anyway...