Learn about Unity's event order when initializing an object.

EventOrderTest.cs

using UnityEngine;

public class EventOrderTest : MonoBehaviour
{
    private bool firstUpdate = true;

    private void Awake()
    {
        Log("Awake");
    }

    private void OnEnable()
    {
        Log("OnEnable");
    }

    private void Start()
    {
        Log("Start");
    }

    private void Update()
    {
        if (firstUpdate)
        {
            Log("First Update");
            firstUpdate = false;
        }

        if (Input.GetKeyDown(KeyCode.Space))
        {
            Log("Before Spawn");
            gameObject.AddComponent<EventOrderTest>();
            Log("After Spawn");
        }
    }

    private void Log(string s)
    {
        Debug.Log(gameObject.name + ": " + s);
    }
}