I think our self-confidence, ie our ability to do things, is formed early on, as well as developed underway. When I grew up, my father always let me order at restaurants myself, as well as pick up our room-key whenever we slept in hotels at our travels. This enabled me to become confident and dare to approach others. And opening for learning more languages than my own.
Another major turning point, was living as an exchange-student in Ticonderoga, NY as a 18 year old. After being able to manage both school and leisure activities, I spoke at our graduation and it made me feel like if I could do this, I could do anything! I am so grateful for that experience. And it was of course also recorded on video, where both my host-families were present, as well as my mother and brother, who had travelled from Sweden to see me. It became a little interfering, since I had built up an Americanized self, but yet, it was heart warming.
I think, confidence is all about doing. Self-esteem and self-worth is about how we feel about ourselves, while self-confidence is our belief in our own abilities.
Later in life, I've held several more speeches, as well as travelled on my own. Not to mention, I've acquired a fluent English to speak and a perspective that I bring with me, affecting me both politically and religiously.