Java field initialization weirdness with primitive values

SubClass.java

public class SubClass extends SuperClass {

  protected int myValue = 69;
  
  public SubClass() {
    // You might think that field initialization will have been performed before this constructor is executed.
    super();
    // However, Java doesn't actually perform all the field initialization for this object until this point in the code.
    // Note also that there's nothing in the source code to say that initialization happens here.
    System.out.println("Subclass constructor continuing");
    outputFirstField();
  }

  public static void main(String[] args) {
    SubClass t = new SubClass();
  }

}

SuperClass.java

import java.lang.reflect.Field;

public abstract class SuperClass {

  /**
   * Output the value of the first field of the object.
   */
  public void outputFirstField() {
    Field f = this.getClass().getDeclaredFields()[0];
    int x = 0;
    try {
      x = f.getInt(this);
    } catch (Exception e) {
      e.printStackTrace();
    }
    System.out.println("Value of field " + f.getName() + " is " + Integer.toString(x));
  }
  
  public SuperClass() {
    System.out.println("Superclass constructor called");
    outputFirstField();
  }
}