Agreed; my point is that the FDA doesn't make that distinction. The FDA's definition of "same performance" is close, but it's not always close enough.
(I once worked on a system that had to special-case pricing for Synthroid specifically because the FDA-approved generics aren't quite the same to a lot of people, and I ended up marrying someone who gets moody when the pharmacy gives her generic Synthroid by mistake.)
Perceived reputation, color and packaging plays a big role in perceived drug efficacy[0], I wonder if a double blinded trial would show the same results you have seen anecdotally.
I'd be interested to see results from such a trial.
Closer to home, we twice found out that the pharmacy gave her a generic when she developed quirks 4-5 days after she started taking a new bottle. Sort of the reverse of a placebo effect -- she thought she was on the brand all along, and she didn't think to check until things didn't feel right.
(I once worked on a system that had to special-case pricing for Synthroid specifically because the FDA-approved generics aren't quite the same to a lot of people, and I ended up marrying someone who gets moody when the pharmacy gives her generic Synthroid by mistake.)