Check out example codes for "is start called after dontdestroyonload". It will help you in understanding the concepts better.

Code Example 1

void Start(){
     DontDestroyOnLoad (gameObject);
 }

// how to call start/awake when loading a new scene on an object
// that has DontDestroyOnLoad.
 void OnLevelWasLoaded(){
     Debug.Log ("A new scene was loaded");
 }

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