At the grocery stores at which I buy most of my food I use the self checkout, so no interacting with humans there.
At McDonalds I order and pay at the kiosks, so no human interaction there except when they hand me the bag with my food. At Burger King and Wendy's I do order at the counter, so I am talking to another human who is maybe a meter or so in front of me.
Every three months I have to pick up prescription re-fills so deal with a human at the pharmacy, and perhaps stand in line there with other humans.
I live in a house in a low density neighborhood, with no other house nearer than 40 meters, although my neighbors on one side have an RV in their front yard that is only about 15 meters from me, with an older couple (their parents presumably) living in it. No human interaction here other than occasionally waving at someone walking their dog on the street in front of my house (about 20 meters away).
Yet I still get the occasional cold-like or flu-like illness in the winter. Who is passing on these viruses to me?