Your mind will grow along with your physical strength. You'll learn something about yourself every week on the max sets (even if you fall short). Every time you get a rep PR or handle a new weight for a heavy single, it gives you confidence and more experience going into the next time you train. The mental conditioning is a part of the process of simply sticking to the program.
It's a really cool feeling when a year or two down the road, you are handing your old 1's week pr on your second set of your current 3's or 5's week. Weight that used to terrify or defeat you will be no big deal, and the lessons learned from those previous weights will shape your approach to new, heavier weights. It is true confidence knowing you can do something because you've earned the ability to do it. There is no substitute for training and experience when it comes to mental toughness.
Best of luck, and good training