I had a mate in High School whose Mum insisted he where one of these lids whenever he rode his pushbike - it's identical!
This was mid 70's - she was ahead of her time and he was 15yo (and mortified with embarrassment).
He'd leave the house with the lid on but stash it in the bush two minutes later; reverse coming home.
Either that or learn to fight.
He eventually managed to 'accidently' leave it behind the family car and his parents backed over it.
