It's great that you're concerned about civility on HN, and believe me I sympathize with the condition of not remembering things one has a degree in. But I'm afraid you misread aroberge—who was trying to reassure the reader that they needn't assume graduate physics—and unfortunately your reply crosses into incivility itself.

We detached this subthread from https://news.ycombinator.com/item?id=11067987 and marked it off-topic.

Yeah, I totally failed in reading comprehension. Sorry.

Griffiths and then Sakurai's quantum mechanics texts should contain what you're trying to recall. They're two I held onto after finishing grad school.

The Griffiths texts for E&M and Quantum were some of the best educational books I've ever read, and unfortunately both were stolen from me as an undergrad.

I didn't read it as arrogant, but a simple list of prerequisites (as viewed by the commenter).