Unfortunately this clip cuts just before the most emotional part. At 01:29 as he's about to break down, he says – this is my memory, sorry, paraphrasing:

"Nothing I ever do again…" – and then, having barely held it together for the last 30 seconds, he has to stop. It brings me to tears every time I watch it.

A man realising the sheer magnitude of the thing he did. It's the most relevant part for humanity today.

Ah! Found it. This is a better clip. https://www.youtube.com/watch?v=BaKyvr4ar1Q