I'm not sure we actually know what our biggest fears are until they appear. I know my son, and only child, was born with congenital heart disease and even after open heart surgery at the age of four years, I feared for his life. He died in 2011 at the age of 51. I understand how blessed I was to have him those years and tried diligently not to let him know how fearful I always was -- hopefully I accomplished that and he never knew or felt burdened by my fears. I also think we all have little "phobic" fears -- like I'm afraid of heights and flying -- but make myself do them so I don't feel like such a wuss! I've found that a fearful emotion takes its toll on one and try diligently to avoid such -- and occasionally am successful.