BJJ and MMA is one of the best example of team sport. You need your coach, your training partners, your support staff etc., to be anywhere near successful. The people around you MATTER.
When egos come into play, things are bound to go downhill.
A few commandments that I have seen other practitioners use, and I personally also try to use :
1) Respect the game, and respect your opponent.
2) Try drilling and rolling with someone lesser, equally and more skilled than you.
3) Tap early, tap often.
4) Remember that no one wants to hurt you on the mats. Whatever happens on the mats, leave it on the mat.
5) Losing or getting submitted specially at white belt level, is one of the best things that can happen. You will end up learning more.
6) Everyone can learn from someone, and teach someone.
7) Introduce yourself to your training partner and thank them at the end of training.
8) Most importantly, have fun, BJJ is not just a sport, its a lifestyle. Take in as much as you can.