Java programming algorithm?

Below is a program that I wrote but I kind of don;t get one thing. I put a while loop in the beginning, and pretty much it says that while response's first character is y, then the program will run. I don;t quite understand then why the program initially runs, if the whole condition is WHILE response's first character is y, THEN the program will run. I am fairly new at this so be kind, thank you!

import java.util.Scanner;

public class methods {

public static void main(String[] args) {

Scanner input = new Scanner(System.in);

String response = "yes";

while(response.charAt(0)=='y'){

System.out.println("Enter password:");

String answer;

answer = input.nextLine();

System.out.println("That's" + " " + answer.equalsIgnoreCase("Noah") + ",");

System.out.println("do you wish to try again?");

response = input.nextLine();

}

}

}