Mike Portnoy was a longtime friend of the late Neil Peart's -- close enough that he was one of few who actually knew Peart was battling brain cancer in recent years. And as news of Peart's death became public on Friday, the prog and metal drum veteran (Dream Theater, Avenged Sevenfold, Flying Colors, Winery Dogs, Sons of Apollo and many more) shared in the collective grief.

"Even though I knew this day would come sooner or later and was inevitability, it's still shocking," he tells Billboard. "I'm still shaking. I'm still speechless. You never imagined a world without Neil, Geddy (Lee) and Alex (Lifeson) walking along it." Portnoy respected Peart's privacy and didn't say anything about his condition, but in the wake of Peart's passing he's more than happy to speak about him -- as a drummer, creative kindred spirit, a hero and a friend...

I first met him about 15 years ago, and at that point I had been waiting my whole career to meet him, but he's such a private man it's hard to kind of infiltrate his inner circle. But once I finally did meet him, he became such a gracious friend and would always stay in touch and send me emails with pictures of his daughter Olivia growing up and was also so gracious when Rush came to town. He would invite me and my son out to the show and to soundcheck and was just such a gracious person.

Once you got to know him, if you were lucky enough that he actually opened himself up to you, he was so gracious and so full of heart, and I'm honored to have become friends with him over the past 15 years.

I discovered him and Rush when I was in high school, back in the beginning of the 80s. He had everything that I always dreamt of becoming. He was just a master of what he did; he played this mammoth drum kit and was the master of the odd time signatures and just had chops for days. At the time, no other progressive drummers were raising the bar to the level he did. I'd never seen or heard another drummer like him. He had the same kind of impact on the drum community that somebody like Jimi Hendrix or Eddie Van Halen had on the guitar community. Like tens of thousands of other young drummers at the time, I just became obsessed with him and everything about him.

That was around the Permanent Waves/Moving Pictures era. Once I got hooked, I worked my way backwards and became completely obsessed with all those albums, especially the progressive ones like Hemispheres and A Farewell to Kings; I even used Pert shampoo! In my high school year book, my future plans were to become the next Neil Peart. He was my God.

What did he do? A lot of drummers would just play a beat, play a groove from the verse to the chorus. They would play something on the high hat on the verse and in the chorus got to the ride cymbal. Neil played his instrument like he was playing a symphony or conducting a classical piece. He was so nuanced and creative. No drummer was playing like that. There are literally nuances in every fill, every groove. Drummers around the world studied that. There's probably no greater air drumming influence than Neil; Every time you'd go to a Rush concert, every drummer knew the fills and was doing them along with him.

To me the benchmark was always "La Villa Strangiato" from Hemispheres. When I heard that, that was a benchmark of musicianship. That was the greatest challenge to fellow drummers, was "Can you play 'La Villa Strangiato?" Learning a song like that was like running the decathlon in the Olympics. And even the most well-known songs and commercial songs, like maybe "Tom Sawyer" or "Spirit of Radio," even though you heard them a million times the nuances in the drumming and all the musicianship -- from all three of them -- is of such a high caliber. You weren't hearing players like that on commercial AOR FM radio.

And he was so much more than just a drummer. The fact he was the band's lyricist and wrote such intelligent, poetic lyrics was a huge influence, as well as the books he's written over the past 20 years or so. After the horrible tragedy of losing his first wife and daughter he wrote the Ghost Rider book, one of the most inspirational books I've ever read in my life. Tour after tour he would put out these books of his travels, about how he would get up and go hiking and go riding his motorcycle for eight hours before even arriving at a soundcheck. He was one of those people that was just so inspirational because he lived life to the fullest.

The last time I saw him was on the farewell tour [in 2015]. I wanted to take my son Max out to see Rush before they retired because my son is a drummer as well and he had to experience seeing Rush and seeing Neil before they packed it in. As always, Neil invited us to sound check and we came and he let my son play his drums and sent him away with an autographed head and some sticks and opened himself up, opened his dressing room up to us -- that's how gracious he was. To me that's such a great final memory of him; It was their farewell tour and my son and I got to share this experience with my biggest drum hero. It was such an amazing final experience to have with him.