One day you are the kid that happily walk out the home door to embrace the future road, one day you are the crying parent staying in the door for saying goodbye. The time you walked out the door your couldn't understand what is in the parent's heart but the time comes when you will understand. This things should be done, is cycle of life. The kid has to have the enthusiasm to walk that door, the parent should endure the pain. As we grow older the enthusiasm disappeares due to such shocks life prepares for us. We need to accept it. Time heals. After some time kid realizes the absence of parent, parent learns to accept the fact straightening the heart.
But it hurts. It is unfair. It hurts. After all what is fair in this world. Fairness is relative. We need to accept. We have a soul that is made to get hurt.