SITUATION EXPLAINED: Josh Kushner wrote Thrive's first investor letter in 16 years. • "Artificial intelligence is the most important technology paradigm of our lifetimes" • "The most important lesson is not a single benchmark or release, it's the rate of improvement" • "The more optimistic we are about the size of a paradigm shift, the more disciplined we must be about where value will be captured" • "Not every company exposed to an important theme becomes important. Not every fast-growing…