I was MORE nervous around people when I was younger. I did not have the coping skills I do now. I have learned to be able to tell if someone is tired of what I'm saying. Before, I didn't know what the heck to do in social situations, so I made mistakes, and became nervous afterwards. Now, with the knowledge which I gained, I'm less nervous in initiating social interactions.
However, when I was a child (ages 5 to 10), I was pretty bold in going up to people, asking them why they are fat, just saying "hi," etc.
Before age 5, I was nonverbal, with severe autistic-like symptoms; I lived in my old world. I didn't go up to people because I didn't know people existed.