I was left to CIO and actually have memories of feeling lonely and scared when I was a toddler. As I got older I often felt ignored and like my needs didn't matter. I felt I was in the way and many things were more important that my needs. I think it has definitely effected me in my adult life as far as confidence and self esteem goes.

As for those who say "I did this or that and mine turned out fine" - do they know that for sure? My MIL says this all the time, but DH doesn't have the relationship with his mother to tell her that he didn't necessarily turn out fine. Physically they may be fine, but emotionally is another thing altogether.