millis() resets every time I open the Serial Monitor

#include <Servo.h>
Servo servo1; 

unsigned long timeElapsed;
unsigned long engage; 

void setup() {

  servo1.attach(9); 
  servo1.write(20); 
  Serial.begin(9600); 

}

void loop() {
  // put your main code here, to run repeatedly:

  engage = 60000; 
  timeElapsed = millis(); 
  Serial.println(timeElapsed); 

  

  if (enagage == timeElapsed){

    *DO THING*
    
  }

  

}