If you don’t believe in yourself, who will? Self-confidence comes from inside you, not from others. And confidence and cockiness do not have to go together. If you think you know everything, you don’t.
If someone is tooting their own horn too much, it is likely they really are insecure. Most successful people play down their accomplishments. So do you want to spend time with the insecure egotistical person who only talks about themselves and how great they are, or the self-confident person who you can actually network with or want to do business with?
Just because you have self-confidence, it doesn’t mean you always will win, but you will give yourself more opportunities. That is because it really all goes back to relationships.
So tell yourself how great you are, but don’t tell me!