I guess the main thing about what you'd generally call a "heavy metal attitude" is being a man. And by that I mean just being yourself and standing up for what you believe in. It has nothing to do with wearing certain clothes or looking a certain way. Hell I'm a 25 year old doctor, I cut my hair short ages ago, I mostly wear "proper" clothes at work out of respect to my patients, but I'm still getting that Manowar tattoo on my shoulder next week and I still arrived at the hospital this morning blasting the new Attacker cd from my car, while at the same time constantly writing cd's for my colleagues who I turned into absolute Scorpions and Whitesnake fans
Also, by being yourself you might not make a good first impression, since us "metalheads" are rarely what you'd call "politically correct" in our conversations, but in the long run you deffinetely gain the respect of everyone around you, because -like Ben said- what you see is what you get, no backstabbing, no alterior motives, just a person who has his act together and knows what he wants.
And a last thing about the thinking factor,. It's true that metal, because of it's lyrics, urges you to pick up an epic fantasy novel and read, watch the news to see what all the politics related lyrics are about etc etc. Deffinetely makes you a wiser and more mature individual.
Oh and about the ladies, I wouldn't know, I'm a doctor, I get plenty of action
