Why am I switching my music likes?

My music likes are always changing and it's annoying. When I first started listening to music, I liked classic rock bands such as the Who, GNR, the beatles, boston, pink floyd, deep purple ..etc. However for the past four years I've been a metal supremacist. I would hate everyother music genre besides my melodic death metal and other metal genres with bands like Children of Bodom, Mors Principium Est, Wintersun, Trivium, Opeth, Disarmonia Mundi, Soilwork, Kalmah, Cradle of Filth. But once again I feel like I am begining to move away from metal into genres like indie rock and alternative such as the Temper Trap, the Killers, Coldplay. I don't want to switch genres. I felt like I was my own person when I listened to metal.