Originally posted here by R0n1n
No, you do not need to have been a hacker to know how to do computer security well, but you do need to know how hackers operate so you now one of the things you are protecting yourself against.
This again goes back to defining a hacker. I ask you this. Why would you need to protect yourself from them? Do you see them as bad people? Do you see them as people who abuse security holes and bugs? Do you view them as credit card thieves and people who act in malicious ways against technology?

To me a hacker is much like MsMittens said. Someone who knows a certain subject so well, that he/she might even know more than those who made the computer/car/hockey team/etc...

Speaking technology wise, they know as much as they can and always want to learn more. They will do thier best to figure out how something works, why it works, or even why it doesn't work. They study why it does what it does. They study why it wont do what it wont. They know what could go wrong and what they could possably do to prevent it from going wrong. They will more than likey know how to program using diff. languages. This of course is assuming they are good. (I'm not going to get into the whole White and Black Hat thing) So, is there a bad hacker? If they are malicious, would they be a hacker? I think not, but some may disagree. Overall, they are the security experts that want to do good. They learn as much as they can about the technology out and put forth thier best effort to help it evolve and make it better.