many among the tens of thousands of demonstrators still jammed into tahrir square repeat that they will not leave until president mubarak steps down. they see themselves on a mission, where turning back is simply not an option. cnn s ivan watson spoke with some of them about their bravery and defiance. reporter: men barricade in tahrir square. cold, battle scarred and filthy, they fought and bled to protect the symbol of egyptian defiance. it was raining. it was cold here last night. yes, yes, yes, yes. and stand and tired and we will continue forever until that system removed. reporter: abdul suffered head wounds during last wednesday s furious battle between opposition demonstrators and president hosni mubarak s supporters. how did you feel fighting other