Picking your battles means knowing who you are by weakness, strengths,abilities,capabilities, & situation of placement. What’s your rank/role in the battle? Your rank/role with yourself? How you perceive yourself? Knowing all that lets you know where you’re supposed to be: The where, when, & how to fight in the battle. Ultimately ask yourself who you are in the grand scheme of the war. Ignorance of this will lead you to make very stupid decisions that will harm you & everyone else. Know you & your place. Work with it. Let everything else be.