I've never been very open with people, most likely because when I was younger I was too open and that got me in trouble. It can be really hard to tell people how you feel and what you've been through. It can be nearly impossible to be honest about your feelings with others, and at times it's hard to show them. At times you may think that you're too messed up to be loved, and so you hold it all in waiting for someone to come along and pry it out of you and accept it. Everyone wants to feel loved, but it's nearly impossible to love someone who you can't be honest with. These are some of the most frustrating things a person who has a hard time opening up can experience.
Brick by brick we build up a wall, full of secrets and experiences; when we meet someone who wants to break our wall, it's scary as hell. It's hard to believe that someone genuinely wants to get to know you and not just hurt you. After all the times you've been broken, it's unbelievable that someone might actually want to help you, so you shut them out.
Being open is hard; there's never a good time to bring up certain things, and you don't want to scare people away. I was told by an old boyfriend that my inability to open up made it hard for him to connect with me emotionally and therefore he couldn't love me. Of course this made me want to tell him all my secrets and sorrows, so I did; then a week later he left. Things like this make us believe that people leave when we open up, so we stop.
Experiences like this only build our walls up higher and thicker. When we open up there's some one there to help bring the wall down, but once it's broken we have to build it up again alone; only this time there are more bricks. Maybe for once we should leave the wall down, maybe only build it up a little; perhaps we should build them but let them be broken a bit easier.
Shutting out the world won't get you anywhere, but spilling your secrets doesn't either. We just have to find a balance.