15. The machine system of claim 9 wherein the machine system is further structured to automatically present as second presentations to the first user thereof, indications of how many there are within a specified recent time period of said one or more topically contemporaneous strangers having substantially same topics of focus or of interest in their minds.
9. The machine system of claim 8 wherein formation of said predeterminations of the likelihoods that the one or more topically contemporaneous strangers have or had substantially same topics of focus or interest in their minds as a relatively current topic of focus or interest that the first user is likely have in his or her mind is carried out by remote servers or by a cloud with which a local portion of the machine system, which is local to the first user, is cooperatively intertwined.