Imagine if one day a person you are interested in dating someone. You pull up their block chain- and in it, is everyone they have dated, have kissed, or have… well, use your imagination.
The information is then of course verified at each step by the branched block chain, i.e. the other bloke (or gal) verifies whether or not they did or were not in a relationship with that person.
Think it isn’t realistic? Hospitals and urgent care places ask you if you drive a car, if you live in an apartment or house, and what kinda work you do.
Because… it has absolutely nothing to do with your need of care at that moment.