dating and "the walls"

What are " the walls" that is described in dating, 

Walls that are there to protect us from getting hurt again. When do we allow our walls to come down ?? Should their ever come down?? If we both have our walls up then how will it progress??.

Walls are good to have up both for men and woman, if for any reason you been hurt in past relationships then this " wall" is like our armour our safety zone, our comfort zone.

It's gonna be hard to lower then walls we all know this but if some one is willing to chip away at that wall and allow you to become at easy with that paste then don't shy away from that embrass it.

Wall is has high has you make it and will lower at the right time with the right person and when you feel more comfortable .