The people around you are your mirrors. They are the ones who allow you to see aspects of yourself--and vice versa. If you spend time with people who mirror your own insecurities, or fears, or judgments, then you're going to see those traits every single day and begin to believe in them. They will be reinforced in you to the point where you decide that is "who you are."
On the flip side, if you spend time with people who challenge your fears, your insecurities, and the parts of you that need "work," you will inevitably change. You will soak up and inherit different traits.
Deliberately choosing the people around you is how you can sculpt yourself.
You want confidence? Hang around confident people.
You want to learn self-awareness? Hang around self-aware people.
You want to learn any skill, any craft? Hang around people who practice those things and do them well.
The challenge with this is knowing when to walk away.
Sometimes people come into our lives at a crucial time because something in us wants to learn--and they too want to learn something from us, and so a mutual friendship begins to form. But every relationship is a path, and knowing when it is time to move on to the next one (whether that means staying friends or walking away completely) is where most people struggle.
You have to be exceedingly deliberate with how you spend your time, and with whom.
- Nicolas Cole (modified by Amr Badran)