Your personal space is likely to be compromised standing in a very large crowd.
Observing behaviour of those around you can provide insight into their traits without knowing much about them.
Their self-awareness or lack there of shines through.
You will see those that constantly moving and knocking into others, overtly loud conversation and general lack of regard for those around them.
Others will stand still and hold their space, barely visible.
Are you self aware enough of the impact you are having on those around you?
If you cannot do it in a crowd, you are unlikely able to do it at work or home either.