And I clicked this submission because of his name, after all the time.
I didn't fully go through or understand the proof, but it was a refreshing addition to the classic problems I had to understand for college at the time.
Didn't need it, just fed my curiosity.
And when I clicked this link, my curiosity was fed again.
Seems like it's worth having heard of him, even as a non-scientist, because his subjects are just so interesting. Reminds me of Scott Aaronson in that regard.
That paper does not prove that Sokoban is NP-hard. It does, however, cite an earlier paper proving the stronger result that Sokoban is PSPACE-complete:
https://en.wikipedia.org/wiki/Erik_Demaine