Nestor is a noun that refers to one who is the leader in a field.
Nestor was a figure from Greek mythology who served as a wise leader in the Trojan war. Today a nestor may refer to anyone known for wisdom and leadership in a particular field.
After giving years of service to the theatre word, Harvey has more recently become something of a nestor in that community. He loves the idea of giving to others all the wisdom he’s gained in his forty years of work.