You can put them up and keep them up your while life but people will still be able to see through them to who you really are. No one is able to hide themselves and protect themselves their entire lives, it’s just not possible if you are involved with human contact every day. Barriers in life can be good thing to protect yourself from being hurt emotionally, but later on down the track you will need to reconsider if its worth keeping them up and building a relationship or friendship on the other side of the wall. It may hurt at first, letting them down, but trust me once a friendship or relationship is established with you both on the same side its such an amazing feeling! Just takes time and a whole lot of trust.