Wait, what exactly did this stranger say to you? Like did he just walk up and start talking about your tires or was there some kind of reason he brought it up? I'm asking because I've had random people at gas stations tell me stuff about my car and half the time it turns out to be nonsense. But you're saying it actually changed your whole routine, so I wanna know what the tip was. Did he show you something with a gauge or was it more of a "hey you should check this more often" kind of thing?