There are many professions from which a ‘layperson’ seeks ‘advice’.
In some cases, the layperson is trying to prove they know more than the professional, in others, attempting to get confirmation of nonsense, and in a few, getting information they won’t pay for.
When approached by a questioner, the first thought should be; “How did this person know I would be at the supermarket?”
As soon as that thought manifests, the response is to look concerned then tell them to come to your office.
If they keep babbling, move off, even if it is to hide in a bathroom, just get away.
These are time wasters. They exist to waste your time.