No matter how good you think you are as a leader, my goodness, the people around you will have all kinds of ideas for how you can get better. So for me, the most fundamental thing about leadership is to have the humility to continue to get feedback and to try to get better - because your job is to try to help everybody else get better.
It was my duty to shoot the enemy, and I don't regret it. My regrets are for the people I couldn't save: Marines, soldiers, buddies. I'm not naive, and I don't romanticize war. The worst moments of my life have come as a SEAL. But I can stand before God with a clear conscience about doing my job.