From where I see it, there is no pattern of purchasing shoes there, unless you truly expect Google AI/servers to track you multi-years long (with the required CPU and storage requirements needed to do so), to establish an unique shoe purchasing pattern, instead of what they more likely are doing, which is looking at recent online and microphone activity.
AKA, Occam's Razor.
And also, how would Google know beforehand, that I will walk into a shoe store and buy shoes, if I didn't do any search for them ahead of time online?