Time and time again do I have to re-iterate that the focus of self-defense is to AVOID confrontation altogether.Not always possible, but if you can avoid a physical altercation, then it's always wise to do so from a legal as well as ethical standpoint.This is where defense differs from fighting or combat.
When most people think of "self-defense" classes,they usually think of some type of unarmed Martial Art based course,but that should only be a fraction of what constitutes a system designed to address true defense.It takes education & training to learn how to avoid situations by being aware of one's own environment by being able to read body language & positioning, language patterns & tone,facial expressions and this simply doesn't come naturally to everyone.
De-escalation or verbal judo is a skill that many street savvy people develop on their own,but most people need some coaching. Methods of escape,either from direct physical contact or broader general physical local have to be addressed as well.Weapons training is a mere afterthought in most "self-defense courses" where the Instructor may recommend things such as pepper spray or even firearms as if these things require no specialized training which simply is not the case.
Defending others or your loved ones is a real possibility,so that must always be considered.Self-Defense or more accurately just "Defense" is a broad spectrum field that requires a diverse study of subject matter. If your only studying one aspect or another ,then your probably doing something other than reality based training.