It was posted many times in the past and I never mind seeing it again - the discussions are always worthy, and there's always a batch of HNers who never heard the story.
I'm one of today's lucky ones, and I really enjoyed the read.
Same here. Great way to wake up.
I've read the story a few times before, but am thankful for the reposting because I've actually been trying to figure out how to build a quantum physics simulator and was most recently stuck on how field interactions / Feynman diagrams came into play. Lo and behold the snippet on path integrals around the lattice, from Feynman himself solving the same problem!