Does friendship really have to wither and die as time goes by, or does a good friend simply transform into an old friend?

Some friends, it seems, requires constant attention.
If you do not call, you are no longer a friend.
If you do not visit, you are no longer welcome.
If you do not tell them about everything that happens in your life, you no longer have any right to know what goes on in theirs.
These are the friends that you might lose if you leave town for a while, get a new job or make a new acquaintance. These are the friends that will not be there when you need help, because you have not helped them first. These are the friends that will pretend that they do not know you when you meet them 5 or 10 years later.
These are the friends I can live without.

I have other friends. Friends that I almost never see, never hear from. I do not blame them for this. They do not call me, just as I do not call them. Still, I consider them friends, many of them even good friends. We do not have the urge to keep close track on each others life that most people seems to have today. They live their life, and I live mine. I know that they are out there, and I know that they will be there for me if I need them, just as I would be there for them. That is enough for me, to know that they exist. I do not constantly have to call them, visit them or hear from them. If they have something they think I should know, I’m sure they will let me know. If they need a helping hand or just wants to talk, they know where to find me. They do not force me to talk, but if I have something to say, they will listen.These are the friends that will still be my friends, even if we do not meet for 10, 15 or even 20 years. Hell, even if we were to never meet again, I would still consider them friends the day I die.
These are the only friends I need.