[Uehreka]

The problem is that people (especially in stressful situations when they’re not thinking carefully) will say things like “that one on the left!” and the person they’re talking to (who is often facing them and thus reversed) won’t think to ask “my left or yours?”

But if you train people to use specifically-invented unambiguous terms that can’t be screwed up, their brains will reach for those words when they’re in trouble.