Like it or not, people will talk about you, even before they meet you. They'll discuss whether they want you on their team or not. They'll decide whether or not they want to interview you or not. They'll decide whether they want to approach you to befriend you or not. They'll discuss how you're perceived in performance reviews. And all of that before they've even said two words to you.
What sorts of things are they saying?
What do you think about when I say Nordstrom? Coke? Apple? Toyota? Lego? Crayola?
All of these companies have paid billions of dollars in advertising to get you to think a certain thing. Nordstrom wants you to think high end fashion. Coke wants you to think cool and thirst quenching. Apple wants you to think connected, seamless, beautiful devices. Toyota wants you to think safety. And so on.
All these companies have a brand that they've established, and spend lots of money building and maintaining that brand so that you think about them at the right time.
For example, I've never owned a Toyota, but I assume that if I did, it would be super reliable, safe, and would last 10 years while I drive it into the ground. That's all based on the branding perception that they've created.
The same is true of people - each person has a brand that precedes them.
When someone is interviewing you for a job, they'll check your credentials, check their networks to see who knows you, check your social networks to see what people are saying about you - all before meeting you. When someone is deciding whether they want you on their team or not, they'll ask other people that have played with you what they think of you.
What are those people going to say about you? What is your personal brand that you've established? Will they think of you as likeable? Smart? Passionate? Ambitious? Musical? Helpful? Thoughtful?
The purpose of a brand is to quickly convey the value of the subject in question. Nordstrom wants you to think that going to its stores will provide you high end fashion. Toyota wants you to think that driving its cars will keep you safe. Nike wants you to think that wearing its clothes will help improve your athletic performance.
What does your brand say about you? What are the values that it conveys? What are the things that you want to be known for? What are the things that you value most in your life? What are the character traits and attributes that matter to you?