For the average home-user, anti-virus software is a must.
I did get a huge endorphin rush when I was able to crack a system because it was like a video game.
Use a personal firewall. Configure it to prevent other computers, networks and sites from connecting to you, and specify which programs are allowed to connect to the net automatically.
I keep my stuff updated all the time. Being in the security industry, I keep up to date with securities.
So the ethic I was taught in school resulted in the path I chose in my life following school.
I love solving puzzles, I love finding my way around obstacles, and I love learning new things about technology.