What should every expert know?

What things should any self-professed UNIX expert have under their belt? I'm looking to fill any gaps in my knowledge. Some things I can think of off the bat: - Shell (interactive and scripting) - Common utilities (grep, ls, etc.) - vi (possibly Emacs too) - Some mix of sed / awk / Perl (preferably all) - Knowledge of networking standards - Ability to set up common programs: A mail server, file server and so on Probably forgetting a lot, obvious and not-so-obvious. What else?