Express breast milk

I have learnt how to manually express the breastmilk by hands, oh gosh, that's so tired, i was so frustrated when trying to use my hand to do the demo in front of the nurse. I told her i have the breastpump so i don't need to learn how to express by hands. She gave me so many reasons why i should learn the hands method including what will happen if my breastpump is out of function. Emmm...if really rosak then i will buy another new one lo...