The mentor.

Some people change the course of your career without ever making a grand announcement about it.
A good mentor does not hand you a perfect career plan. Often, they simply see something in you before you have learned to see it in yourself.
They may put your name forward for an opportunity, tell you the truth when you need to hear it, help you recover from a mistake or remind you that one difficult period does not define your ability.
More than advice
The most valuable mentoring is rarely a series of polished monthly meetings. It is built through trust. It is the person you can call when you are second guessing yourself, deciding whether to stay or leave, preparing for a difficult conversation or trying to understand a part of the industry that still feels closed to you.
A mentor can give context that a textbook cannot. They know what it feels like to be the least experienced person in the room, to be overlooked, to lead for the first time or to wonder whether they are ready for the next role.
What good mentoring feels like
A mentor should not try to turn you into a copy of themselves. The right person helps you think more clearly, make your own decisions and recognise the strengths you may be underestimating.
They challenge you without making you feel small. They tell you when your work can be better, but they also make sure you notice when it is good. They do not create dependence. They help you trust your own judgement.
Be the person who opens a door
Mentoring does not only belong to the most senior people in the profession. You can be one step ahead of someone and still help them. A thoughtful conversation, an introduction or a clear answer to a question can alter the way somebody sees her future.
Most of us can name at least one person who made work feel more possible. The best way to honour that support is to become that person for somebody else.