Why is this not working?

I have a simple piece of code to decrease an object's "life" when I press the x button. When I play the game and press x, the life goes down random amounts and does so until it is deleted. Please can you help me find a solution to this or even tell me why this is happening and what I have done wrong.

Thank you in advance

This is the code which I am using:

 public int life = 10;
 
 void Start () {

 }

 void Update () {
     if (life < 1) 
     {
         Debug.Log ("You Win");
         Destroy (gameObject, 1f);
     }
 
     if (Input.GetKey ("x"))
     {
         life = life - 1;
     }
 }

}