Developing concern for others, thinking of them as part of us, brings self-confidence , reduces our sense of suspicion and mistrust, and enables us to develop a calm mind.
It seems to me that self confidence and the ability to stand one's ground are essential if we want to succeed in life. I am not talking of stupid self-assurance but of an awareness of our inner potential, a certainty that we can always correct our behavior, improve ourselves, enrich ourselves, and that things are never hopeless
Once you develop confidence in your own ability, you'll be able to make a real contribution to creating a better world. Self-confidence is very important. Not in the sense of blind pride, but as a realistic awareness of what you can do. As human beings we can transform ourselves by our good qualities and reducing our faults. Our intelligence enables us to judge what is good from what is harmful.
How was I able to live alone before, my little everything? Without you I lack self-confidence, passion for work, and enjoyment of life--in short, without you, my life is no life. [Written to his wife, Mileva]