Exactly! And in the zones you're constantly on your guard for things but it's not possible to be On all the time so you have to trust just to get the sleep needed to keep going exactly what if you trust in the wrong place or the wrong person? Also, just by dint of living in the Zones you're pretty much placing your trust in technology - ray guns, water purification, etc - to keep you alive and you're bargaining with other people for technology and trusting that they are not going to screw you over on the value of the item or its functionality. It's not like if the item doesn't work you can just nip down to the store to get a new one. I am facinated by the idea of the dust 'verse where if you trust the wrong person then you can die and there are so very many instances where you're pretty much forced to trust.

Plus, there is also that level of having to trust yourself to make the right choice.