On Thursday, Bill Gates announced a new, faster timeline to give away his fortune — and close the doors of the Gates Foundation, one of the world’s leading global-health philanthropies.

Over two days last week, he spoke to me for an exclusive interview to explain his decision — and why it made sense to him, at a critical moment in public health, when the Trump administration’s steep cuts to foreign aid have thrown many global-health priorities into jeopardy.

Here are some of the key takeaways from that conversation.

Before the foundation shuts down in 2045, Gates has committed to it spending $200 billion, beginning now.

All told, the foundation has spent$100 billion over 25 years. It now intends to double that over the next two decades, focusing on three key goals: that “no mom, child or baby dies of a preventable cause”; that “the next generation grows up in a world without deadly infectious diseases”; and that “hundreds of millions of people break free from poverty, putting more countries on a path to prosperity.”

These are astronomically ambitious goals, but Gates and his team believe they can be achieved in a compressed timeline — just 20 years, instead of an original vision that would have lasted for decades longer — and he is pouring nearly all of his remaining fortune into making it happen.

In the next 20 years, Gates believes, progress will be ‘incredible.’

“This is a miraculous time,” he told me, with the most exciting work the foundation has ever done sitting in the R.&D. pipeline now, waiting to be delivered.

It was almost hard to keep up with his survey of breakthroughs: on H.I.V., on tuberculosis, but also on more obscure and neglected diseases like lymphatic filariasis and visceral leishmaniasis. He predicts that maternal-mortality rates in the developing world could be brought into rough parity with those in the rich world, and that childhood deaths could be cut in half.