Pianists can be loners just because they spend so many hours in a practice room. I always advise my students to be as creative, open-minded, flexible, social, hardworking, humorous, honest as possible. You need to understand and love other art forms, relate to many professions, know how to begin and see-through projects, know how to relate to people and help people, be socially aware, be politically savvy, well-read. Be a complete human before–or while–you try to be an artist.