When I was young, my parents made me feel like I was ugly. (No exageration.) Therefore, I always looked at the ground when walking, and rarely looked into anyone's eyes when speaking. I felt like it hurt them to have to look at my face. I definitely had low self-esteem.

Also, later, I felt like if I didn't look at someone when I was talking to them, they could only know what I said to them and could not look into my eyes and see anything else. It was a way to protect myself from them knowing too much about me. And, if they had anything negative to say back at me, they also would not see the tears in my eyes if they hurt my feelings.