I live in London, don't own a car and occasionally have to take the bus to get to places.
Yesterday I got on the bus and counted five people not wearing masks. Two of them didn't have any masks on them at all, so might have been exempt or might not - who knows.
But the other three were wearing masks around their necks but not on their faces. The bus was quite busy and I was forced to stand near to one of these people, as there was nowhere to sit.
How selfish can you be to get on a bus and not give a damn if you infect other people? Does it really take much to move the mask from your neck to your face?
They were all young people so perhaps they simply don't care, as the risk to them is lower than other age groups. But they could try thinking of other people.