Can Your Heart be too Big?

On Saturday, I was talking with a friend about recent events occuring in my life and she told me that my heart was too big. She told me that I took things in way too much. My question is can a person's heart really be too big? I must admit that a lot of things would be so much easier to deal with if I could close myself off emotionally when i wanted to. To not get hurt emotionally through relationships and circumstances would be a great thing! BUT, i'm not the kind of person who can do that at will. At most, i can pretend indifference but not really close off my emotions from people and events. I think it largely depends on the situation and extenuating circumstances, in some cases you need to have an open heart and with others you do need to close it off. I just find it so very hard to do the closing off part. Anyone else have thoughts on the subject?