A Martial Art
Very shortly after I began studing martial arts, friends and family would ask me" why was the art so violent?" or "why are you so paranoid, do you expect an attack anywhere at anytime?" To answer the 2nd questions , "yes , I do expect an attack anywhere, at anytime." Criminals do not wait for a person to be ready for an attack. Mentally unstable or drug abusing people attack whenever or wherever they want or need to.
As a beginner in a martial art,it is a natural progression of training to go from unaware to hyper sensitive to a balanced medium concerning awareness. As an instructor I am only too happy to hear of stories from my students wherein they tell of their awareness to danger. As they gain experience, they "tone down" their alert meter to a reasonable level.Soldiers, policemen ,security personel and others that need "hyperawareness" learn to turn off and on the ability.(Luckily for the rest of us).
As to the violence question, i usually reply that in order to face a violent ,crazed or drugged up individual, a martial artist may have to react as violently or moreso in order to protect him/herself and / or family. Again, as with awareness, it is better to know too many ways to deal with violence than to be underprepared for a situation.Hopefully, you will never have to deal with any violent situations, but if you do, Martial Art training can be useful.
Sensei Doug