[BurningFrog]

One way software is different is that you're always doing things you've never done before. Because if you've done it before, you can just reuse that code.

This is probably not how the refueling nuclear aircraft carriers projects work.

That said, it's usually not quite as completely unknowable as your last sentence. Then again, it frequently is.

The real tension is about trust. When people think engineers are lying about their estimates.