Back in the 70's when I first started riding a moped the only biking gear I wore was a open face helmet bought from my mothers catalogue
It was all I could afford

Back then even a full face helmet was a bit of a novelty to us youngsters.

Cowboy boots were in fashion then and they acted as bike boots.

Back then I rode a few times down back lanes, etc, with no helmet on.
If you have never tried it - you really should on a nice closed straight safe road.
You don't half feel exposed and it will make you ride very carefully the other drawback is your are open to the elements - the british climate is rarely warm enough and when it is you get bombarded with all sorts of insects in your face and hair.

Anyone remember the old greaser back in the 70's who rode the old brit bike around the chippenham / calne area.
He hated the jap bikes and also was anti crash helmet so he wore an open face helmet with the strap as loose as possible.
Used to meet him coming the other way with his face and head all contorted because his helmet was half off his head like a parachute.

The good old days