Saying goodbye is difficult. 

Not the type of goodbye you'd say to someone at school, only to see them the very next day, or the type of goodbye you'd say to your aunt at a family reunion. 

It's the kind of goodbye that means losing somebody relatively important. Someone that cared for you in your highest, your lowest — your everything. 

Until you and that person are nothing but people that eventually move to the back of your minds. 

That's why saying goodbye is difficult.