DAVE MUSTAINE: Marty was such a great guitar player, it caused a crisis of confidence in me. Voices inside my head starting picking on me. Going into the studio brought all these raging doubts crashing down on me. I stayed in the lounge or the kitchen, feeling discouraged about my guitar playing. Until then, I thought of myself as one of the best guitar players in the world, but here was this new guy — granted, he was really good at lead, but he was not a well-rounded player; not a rhythmic-lead-acoustic-electric-songwriter-lyric-writer-producer-engineer. He was not all these things. He was only a lead guitar player. But, in my diseased mind, he still was so much better than me that I simply crumbled. I thought, here, I've been playing all these years, and I should be so much better.
Surprised he’s willing to admit this.