Well, as you all must know by now, Dinosaur Jr HAS reunited and are allegedly planning to record and release a new album together. Dinosaur Jr broke up because J Mascis was a very controlling person. It was over creative differences. We have to remember that the band members were very young when they started getting big. They were barely out of college and they were all rather immature. They were stuck in a van together for weeks at a time and annoying personal ticks soon became huge problems. Besides, J never actually hit Lou with his guitar. He tried to but Lou blocked J with his bass. So technically, J hit Lou’s bass with his guitar.