I took years studying classroom management before I finally got comfortable with it. Now I am at the point where I don't worry about it much anymore. I have figured out a few things that work for me in this area and I feel like I have a good handle on dealing with student misbehavior.
In fact, I am at such a place of comfort with classroom management that I can easily become overconfident. This is a problem.
Overconfidence can easily lead to laziness or lack of focus.
No matter how good or comfortable you get with classroom management, it will never be completely easy or stop being important. Get organized, keep your emotions in check, and don't lose focus.