Self-confidence involves accepting yourself, knowing your strengths and weaknesses, setting realistic goals, and handling criticism. It refers to being happy with who you are and what you can do, though levels may vary depending on circumstances. People without confidence may doubt their abilities, undermine themselves, and constantly fear being found lacking. Increasing self-confidence involves recognizing your strengths, treating yourself with kindness during failures, setting achievable goals, and slowing down intense emotions to think logically.