Saddest part of letting go..

I thought the saddest part of letting go is when you've had enough,when you still want to be with the person but he dont want you to be around anymore,but then i was wrong i realized that is it when you both want to be with each other but the only choice you have is to let go of the person you love no matter how much you loved each other regardless of the happiness you feel when you're together but you have to let go because it's the best and right thing to do :( ..