Mossberg: Apple's new watchOS 3 shows the virtue of starting over

The tech industry loves to extol its ability to recover from failure. It regularly brags that, in contrast to older, more staid sectors of the economy, tech sees failure as a learning experience and bounces back with something different and better. But that’s a bit of an exaggeration. Lots of companies try to improve on failed or disappointing products, but few overhaul them completely and start all over. Mostly they unveil more modest iterations they hope will do the trick. Microsoft’s Windows 7 fixed the worst problems of the awful Windows Vista, but it was mainly a modern