How do you become a Metalhead, and what makes you one?

I understand you have to love metal to be a Metalhead, and bang your head occasionally to music... but is that all? Is there more to just liking and banging your head to Metal? Also, I like Killswitch Engage, Cannibal Corpse, 3 Inches of Blood, Devil Wears Prada, Mastodon, Metallica, Slayer, Megadeth, Anthrax, Children of Bodom, Exodus, Death, Daath, Disturbed, Avenged Sevenfold, Bullet for my Valentine, Job for a Cowboy, As I Lay Dying, Otep, Becoming the Archetype, Goat, Woe of Tyrants, Testaments, IWrestledABearOnce, and Suicide Silence... and Bang my head, does this make me a Metalhead or is there more? By the way, I named this off the top of my head so I don't remember all of the bands I like.