I'm sitting here reading the firewall book, and looking around in the firewall at the same time. It's nice. I know not to make changes, but my understanding of the tool has increased like you wouldn't believe. And I'm only on page 8 of the book. It's just nice to see what I've been doing with the firewalls and actually know what I'm doing instead of being a trained monkey.
While looking at that. I realized I've hacked a couple of boxes in the last month, with the sole purpose of getting administrator level access. One firewall, one Linux server. The linux server scared me though, since xen source doesn't use shadow passwords. I'll let you figure out why that scares me.
Once again, I realize I get paid to do what I like to do (most of the time).