Zimmerman carried a gun to protect himself - as a result,

[Lizzie Poppet]

32. People sometimes do both.

That is to say, that even in cases of legitimate self-defense, your life will change if you use deadly force against another human being. You will have just begun a long, expensive, and probably nerve-wracking involvement with the criminal justice system. You may be sued by your attacker's survivors. Unless you are a sociopath, you will suffer from the serious psychological shock that a person feels after killing (no matter how justified).

Choosing to carry a weapon for self-defense is a monumental decision, and one to be made only after careful consideration of the ramifications and honest self-examination.