Humility doesn't mean that we are quiet and obscure. I'll give an example: we may see that within ourselves we have bits of aversion, bits of craving, etc. By seeing the suffering that arises from this unbeneficial conditioning within ourselves brings us a certain humility. With this humility we don't raise ourselves above other people who may have that unbeneficial conditioning within themselves. However, that doesn't mean that just because we have these things within ourselves that we are under-confident. We also see the other sides of ourselves, the beneficial conditioning that we have. Similarly with this humility, just because we have some beneficial conditioning within ourselves we don't raise ourselves up above others, because we also recognize other people have these beneficial qualities, too.
Happy and confident – there is a tendency within us that when we are confident about ourselves we may forget about all the thoughts of self, and instead we just manifest our understanding, or giving, or helping without creating so much of an ego and without comparing ourselves with others as much. So there's confidence, we are not getting caught up in what we lack or with how wonderful we are, we are just happy to be who we are and manifesting that. Whereas sometimes when there is a lot of under-confidence, we try to overcompensate for that by becoming very talkative or outgoing. This is to try to overcome the fear we have, or the feeling that we are not okay, by searching for and receiving the praise and love of others. Another person who may act like that type of "happy and confident" may be covering up their feelings of lack within.
So sometimes when we are truly happy and confident, we don't feel we have to impress others so much. We can just be quiet and just be who we are without needing the attention of other people or beings. And we are okay with being unnoticed. So we can be okay with not being noticed and we can be okay with being noticed.
Humility doesn't mean that we put ourselves down in relationship to others. Humility just understands that we are human and that due to our humanness we make mistakes, due to our humanness we will not be perfect. So we don't need to project that we are okay, great, perfect, etc., and we don't need to get upset when we make a mistake so much. We have more humility and realize that all human beings make mistakes and so it's easier for us to acknowledge our own mistakes without putting a lack of confidence on ourselves. We can see that, "Oh, we made a mistake, we are human. All humans make mistakes from time to time and we don't have to take it personally and start to beat ourselves up for it." Through humility and understanding our humanness we have compassion for ourselves and we are able to forgive ourselves more easily. And then it doesn't interfere with our sense of self-worth. If our self-worth depended on never making a mistake then most people wouldn't feel very good about themselves at all.
Sometimes, if we make a mistake, and able to apologize for that mistake, and able make efforts to correct the mistake, then that would give us a sense of self-worth rather than just expecting that we would know everything possible and never make a mistake at all. Also, we can realize that oftentimes by making mistakes we actually are able to grow and develop in the process. In this way, we can learn how to prevent making those mistakes again in the future, then we don't project an ideal of ourselves onto ourselves as having to be perfect all the time.