Being completely unaware of anyone else:

• Standing in doorways, using your phone or having a conversation
• Talking loudly when inappropriate, when I’m in pain at the doctors, I don’t want to hear about your roses
• leaving your shopping trolley blocking the aisle sideways in the supermarket while looking for your stuff
• driving down the middle of the road so everyone else has to pull over, when there’s plenty of room for two cars to pass
• stopping in the middle of the road without indicating, while: looking for your destination, or having a conversation, or deciding what day it is
• riding your delivery bike down the footpath at high speed weaving between pedestrians

As Jean-Paul Sartre said, “Hell is other people”.