Make inspector show changes of class variable value in function?

Hope you understood my title (question). This is a simplified version of the code to make the concept clearer:

 using UnityEngine;
 using System.Collections;
 
 public class customClasses : MonoBehaviour
 {
     public CharacterAttributes playerAttributes = new CharacterAttributes();
 
     public void Start()
     {
         playerAttributes.level = 12; //these two changes does now show
         playerAttributes.name = "Cpt. Awesome"; //but i want these changes to show
     }
 }
 
 [System.Serializable] //makes the class variables show in inspector
 public class CharacterAttributes
 {
     public string name; //shows with value "" (this is correct)
     public int level; //shows with value 0 (so is this)
 }

So... i have successfully made the class variables show in inspector, BUT not the changes i perform in the top function "Start"