I disagree. I looked up dates to verify. I suppose if you got your information from mainstream media it would seem like it went as you say. But it is a fact that the spread started in December 2019 [1], and the Diamond Princess data was available in February [2], and lockdowns started in March [3]
I don't see how this contradicts what I said. Serious lockdowns started in response to hospitals getting swamped, too late to actually stop the virus but just in time to barely keep health care afloat. As such, I fail to see how you could call such a response "irrational" unless you've memory-holed the corpse trucks, treatment tents, and so on.