Does growing up mean we have to grow apart?

Unfortunately, we all have to grow up. This is something I have been resisting for YEARS now. But I fear that my time might be drawing near. I've grown up with a fantastic group of friends that I am mostly still friends with to this day. They are the most wonderful, beautiful, intelligent, funny, silly and fantastic people I have EVER met in my life (I realize I may be a bit biased), and I wouldn't be who I am without them. They are always supportive and I am pretty sure that if I murdered someone they would find a way to say that the person had it coming. I can always count on them to talk with about something, from my fear of being a failure in life to what to wear (seems trivial, but really...it's not). Sure my friends annoy me sometimes...but who ISN'T annoying sometimes? I am the first to admit that I will drive you crazy if you spend too much time with me...hell I drive myself crazy sometimes.

Yet lately I feel as though I am being left behind, that we are all growing apart. This is understandable, people obviously change as we grow older, but I was under the impression we were supposed to embrace those changes. I have clearly changed too in these past years away at University. I have made new friends and hopefully changed slightly for the better. It would be odd and sadly pathetic if we all stayed the same and there was no personal growth. Of course there are always people that change for the worse....or the characteristics that annoy you become more pronounced. I used to be able to put up with a lot more from certain friends, and lately I find myself rolling my eyes at their selfishness and wondering how they can be so freaking self-absorbed. I wonder if they have always been this way and it is me who changed...or have they changed and it is simply more noticeable now? Maybe I will never know. What I do know is that I am less likely to put up with it now. I won't let them guilt trip me into giving them a ride, or always talking about their problems or making me think that I am the bad friend. Is that a change for the better? I would like to think so. I don't want to feel used by them anymore, that is not how a friend is supposed to feel.

I feel as though I am losing one friend in particular, and it just breaks my heart. I don't know when it happened...I can't pinpoint the time. I wish I could, because I want to change it so badly, but I just don't know what to do. This girl is my other half...my better half actually. She's incredible and never ceases to amaze me with her strength and beauty...both on the inside and out. She has been through more in life than I can even imagine and yet she is such a person, it just amazes me. Yet all that she's been through, she has never hesitated to help me with my problems and talk to me. There is one particular time that I never could have made it through without her. Even though I was surrounded by other people who were supportive...she was the one I needed. The only one who would listen to me...and see through the lies I was telling...that I was ok. Because she knows I wasn't. She used to be the one I would turn to first...I always wanted her opinion first...I knew she would tell the truth, whether it's harsh or not. She makes me confront my feelings, even when I don't want to. Even now that I feel we aren't as close, she's still the only one I can talk to about specific problems...the ones that I wouldn't even dream of turning to my other friends for. Still, I feel as though there is a space between us...and I just can't get through it. There is awkward silences where there used to be comfortable silences...things left unsaid.
Maybe it started because she thought she was a bad friend...but she wasn't. At least I don't think she was, she was the only one with the guts to tell me that the guy I was dating was a jerk and was wrong for me. And she was right, I wish I had listened to her sooner...actually I wish I had listened to her at all, maybe then I wouldn't feel like a fool. It's possible that it's because I feel slightly hurt and replaced by her boyfriend and new friends...jealous of them. It's a stupid thing to think...but I still think it. It's not as if I haven't made new friends too, so I know I shouldn't feel this way, but I do...and I know it's a bit selfish, but I never said I was perfect. I used to be the one she turned to for help...and now I find out things that happen in her life through third parties or she tells me as an afterthought.
I too, find myself hesitating when talking to her now...maybe she's just had enough of me...I couldn't blame her. Honestly though, I just miss her and spending time with her. It feels as though I haven't seen her in years when in reality I just saw her or just talked to her. I know that we will always be friends...but can we get back to what we used to be? It seems almost impossible, but I will never stop trying.

It just makes me wonder: why does growing up mean that we have to grow apart?