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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