It is one of the hardest decisions to let a friend go, but sometimes you simply grow apart. This has happened more than once in my life, but I firmly believe that people come in and out of your life for a reason.
We teach each other things without realizing that we are.
We provide comfort when we have a problem that can be related to someone.
We provide challenges to each other when we need that extra push.
But, I believe it is not about not wanting to let go ... it is about remembering why they were in you life in the first place.