That is correct. I was sitting in center field bleachers and remember it like it was last night.
Even before Cal announced he was retiring, I went ahead the day the individual tix went on sale that January or whatever and bought a Yankee Stadium ticket as it would have been his last ever game. And I planned a whole mini-tour of AL East parks to see his last game in those parks. So I had his last game ticket for NY, Boston and Baltimore bought in January, plus trips to Philly, Pittsburgh, the Martin Guitar Factory in Nazareth, and a Ray Davies Storytellers show in Falls Church VA.
The downside was that 9-11 occurred and all games were postponed and eventually rescheduled about two weeks later. The whole trip was pushed back. But the Yankee Stadium game, which was supposed to be his last, ended up being not the last game. That game was called after 15 innings due to rain. Cal went 0-8, I think.
So I ended up paying $200 for his actual last game, which was the one at Camden Yards. Still a thrill, but ended in a disappointment.