My mom would play hair metal when I was a kid and when she met my stepdad, he brought classic heavy metal like Led Zep and Sabbath to the household. This was the early 90s so I associate stuff like Thin Lizzy and AC/DC with being woken up to do yardwork in the summer. I started listening to the mid-90s trendy stuff like Tool and Korn with my friends, and one of them started playing Slayer (Seasons in the Abyss, I think) while we were skateboarding one day. I was pretty into all the nu-metal stuff at that point, and Slayer was the first real fast, brutal band that blew me away with how evil and cathartic it sounded. I also accidentally bought the Mortal Kombat OST which had Napalm Death and Fear Factory on it, which remained two of my favorite bands for years. I would stay up late Sunday nights in middle school (like '98, '99) to catch an extreme metal radio show in Phoenix and try to tape it so I could listen to it on my Walkman at school the next day.
In high school I kinda fell out of metal and got into Radiohead and Neutral Milk Hotel and weird art-rock, which still holds a spot in my heart, but then stumbled upon an Eighteen Visions/Lamb of God/Five Pointe O/Mushroomhead show at a tiny venue and it wrecked my shit and I dove deeper into metal. I started jamming with a drummer who turned me onto Discordance Axis and At The Gates and there was no turning back.
It's almost like drugs. I keep finding something new that makes me feel this intense floaty jaw-dropping feeling and then I get used to it, and then find something else. The newest thing for me is some black metal, and who knows what the next will be.