You will never be able to understand.

We have all had it.

You start a new job, and somehow conversations with your new co-workers turns to "oh you are into music? What kind of music?".

Say just "Hardcore" and people will assume you mean happy hardcore. My substandard answer is "Hardcore Punk". Most will not question this.
Some ask "Oh? Like what bands?"
"You won't have heard of any of them," I usually respond, as politely as possible. "They are pretty underground bands."
"Try me." Most that say this like to think of themselves as music connoisseurs.
"Sick of it all? They are my favourite band." I say with a bemused grin.
"Oh. I have never heard of them."

But how do you explain your love of hardcore to someone else?

"I have been going to shows for 11 years now. There is nowhere I feel better than when I am stood in a room full of people climbing on top of each other, trying to get the mic off the singer.. I enjoy nothing more than being surrounded by people losing their mind, singing along.. I love the feeling of finding a new band that impress me more than a band has done in months... knowing that great things are in store for them.. When my favourite band are onstage, and im singing along, nothing else in the world matters. Anything that has gotten me down has been forgotten..
When I am walking down the street on the way to work, and a song that i love comes on shuffle, I smile, like I have a secret that none of the suits I am surrounded by will ever know about.

I have travelled thousands of miles to see bands. I have spent more money on hardcore then I care to think about. I have seen hundreds of bands. I have made the best of friends. It IS my life. It will always be my life. You may have "grown up and had a normal life" but the sad thing is that you will never get to feel what I feel every day. You will never ever feel so much passion about something that makes your life infinitely better. And for that, I pity you."

Most would look at you like you were insane.