I have found that the best mentors I have had throughout my career are not chosen for me but rather by me. They are the individuals without the 'title,' the ones you are comfortable having unrestricted conversations with, you trust and value their POV.  

The words of wisdom and experience you have gained throughout your relationship with your mentor can help guide you even if you find yourself in a 'loss' situation. The guidance you have used to make decisions help shape your own story.