Willingly taking another human life affects everyone differently, but most feel some sort of guilt. Rationalizing it with mitigating circumstances (self defense, defense of another, defense of home) helps somewhat, but unless you're a total monster, it gets to you. It gradually bleeds into your conscious thought as time passes and the rush of adrenaline fades, and settles on your conscience with the weight of a crushing wall of water.
You carry it with you daily, like your ID, and like a scar it becomes a part of you. You begin to identify yourself by that brief moment in time despite the rest of your accomplishments and failures in life, due in large part to the guilt and social taboo placed on the taking of life. It is a ritual. As more time passes, the ritual gives you a strange comfort that only you understand. You find yourself completely assured of the fact that strangers in your life who know nothing about you can see your history of violence through your eyes like a movie projected on a wall. At times you're ashamed, and break eye contact abruptly, other times the violation of it enrages you and you defiantly stare through them until they look away, intimidated.
People who have never experienced it cannot possibly understand. Not the PhD's and shrinks, not the grief counselors, not even your loved ones can fully appreciate your emotions and thoughts.
It is a heavy cross to bear, indeed. But it is a necessary weight to bear sometimes, to prevent others from harm or suffering.
It is the second greatest sacrifice a person can make.
