If you want to be good in this sport, you must learn to train alone and learn to enjoy the hell out of it. The best in this sport do so AND prefer it. Those that can't train alone and say they perform better in a group setting or with music playing or with people around are simply weak minded. It's the equivalent to only training everything you're good at, every movement that makes you feel elite, then when you're asked to do shit you suck at, you do just that...suck. Of course we'd love to do things we excel at, but most of the time we have to do the shit we don't want to do when we don't want to do it. Why? Because it makes us better. Yeah it's not as fun, it's tough and its really fucking boring but if you can learn to quiet your mind and push yourself past limits when no ones watching, imagine what you can do when this isn't the case. If you can break that little voice in your head, then breaking your oponents will be cake. It hurts to go hard when no one is there to push you, so by training alone you learn to do it yourself. Your PR's don't get celebrated, they just become routine and no one cares about if you are or if you aren't, except for you, so that's why you do it and do it with intent. Training alone builds character but most importantly, it builds mental fortitude. Plain and simple.
So, next time you put off a training session because you can't bro out or because your pandora station lost its connection, re-assess how important your training goals are to you. If you want it bad enough, nothing should be that hard, especially training by your lonesome.