At the age of about 12 I heard Gary Moore "Over The Hills and Far Away" and absolutely loved it. Just played that track over and over again. Up until that point I had expressed zero interest in any music other than whatever my friends were listening to. A few months later I was round at my cousin's place and he lent me his entire vinyl collection including the first 7 Maiden albums, Rush "Moving Pictures", Saxon "Power and the Glory" and UFO "Strangers In The Night" among others.
Saxon and Iron Maiden stood out the most from the selection and I promptly went out and bought the same 7 Maiden albums myself. The first record I bought blind was "Slowly We Rot" by Obituary, looking back I bought it more to shock everyone rather than because I had heard any of it already and liked it. I got to appreciate it's brilliance very quickly of course but at the age of 13 picking up that record and viewing that artwork with my "young, dumb and full of cum" mentality I was never going to not buy it!