These practices certainly change you, especially if you have unintegrated values or mixed experiences with violence, aggression, personal physical power or the fragility of life. Some of the changes are long-lasting. Some of them are dramatic. Others are not apparent or go away if you abandon your practice.
Increased awareness of violence is very common. You're spending time learning how to be more effectively violent. You're learning to deal with violence directed at you. Of course it's going to be a larger part of your consciousness.
We construct our psychic landscape through stories. The stories in class are mostly related to fighting or learning to fight.
We model our behavior on the people around us, especially the ones with higher status within our groups. You're part of a group that is held together by a shared interest in the subject, and you pattern yourself after people who are particularly good at it.
The body conditions the mind at least as much as the other way around. The way you move is being repatterened around violence.
Some people aren't comfortable with this and either leave martial arts entirely or drift towards groups which stay away from these issues and the changes they compel. That's why for instance the "It's just Taoist health exercises" schools of Taiji and the "O-Sensei tells us that if you take part in a fight you have already lost" threads in Aikido are so popular.
Other people just get way too into the whole blood and bones aspect. You know the type. There's the Mall Ninja and the guy who touches himself while he thinks of the seventy nine ways he has learned to kill someone with a toothpick. If a person is basically mistrustful or sadistic those predispositions may be heightened.
Fortunately both of these non-productive and really rather silly extremes are temporary. The tendency comes and goes with the development of new capabilities and as perspectives change. Eventually the experience is integrated, and one moves on. As long as one is growing and in a decent social environment the usual pattern is for a return to a healthy balance. The balance may be very different than where one started. It will certainly include increased awareness of violence and an attitude towards it which is more rooted in shared experience and competence than in fear of the unknown.
An advantages of acquiring a little skill in this area is that one becomes more sensitive to it. Having something explained is hit or miss. Seeing makes an impression. Direct physical and emotional experience, especially from having actively done, causes lasting changes. One becomes more aware of threats and the tendency towards violence in others. Whether this is paranoia or simply a clearer view of the world depends on the level of risk one assigns to the data and how accurate the impression is.
There's also a level of play? simulation? trying out the new tools? Something like that anyway. You look at things in light of what you can do and how you would react. If you haven't completely internalized your training and experience they will push themselves forward in your mind. Every crime story in the news becomes a chance to wargame the situation and come up with a better outcome. Every possibility of conflict becomes a sure thing.
Like I said, it generally evens out.
But it appears very different to anyone who hasn't had a similar experience.
I was going to come up with a different example. Heck with it. Think about sex. At one point in your life it didn't exist. Then it was something strange that made grownups act stupid. Then it was a mysterious thing that was going to be important some time Real Soon Now. Then came puberty, first crushes, and everything that went with them. Even if you had the best fact-based theoretical education it didn't prepare you for how it would change nearly everything.
Eventually most people find a way to fit in that part of adult life with the rest and put it in perspective. Some sad few never manage.
Same sort of thing.
if I was paranoid it was for good reason. Living out on the mean streets of several major cities one develops a sense of awareness that is borderline paranoia. But paranoia isn't necessarily always fear. It could be just plain ole' common sense screaming at you that you're going to be in the right place at the wrong time (or is it the other way around?). 
