Friends?

Well, I've always believed that there is no use of having friends, 'cause what's the point of wasting your time with someone that'll eventually walk away? That'll disappear one day. I asked many of my friends, what's the use of having friends? Every and each one of them said "one day you'll need someone to talk to, someone to have fun with, someone who understands you, someone who'd be there for you no matter what" Well ,I didn't deny that that's true, but even though, those friends wont last 'forever' as they say, someday. One day they'll 'move on'. Now, when I told a friend that they'll 'move on' she said, it's not a love relationship so they 'move on', well I know it's a freaking FRIENDSHIP, what I meant by saying move on is that they'll grow up, they'll start working, get married, have kids, and eventually they'll forget about each other. Once I was in my friend's place, it was three years back, I think, we were very close, when my friend asked her mom, did you have a best friend when you were our age? Her mom answered "Yes". "What happened to her now? Are you still in-touch? Do I know her?" My friend asked. Her mom said, "No, you don't know her, 'cause since I got married, we didn’t see much of each other, we didn't 'hang out' much." Ha-ha. That proves my point. See, I always think, what's the use of having friends if they'll eventually forget about us? When I am close with someone, sister, friend, etc... And I talk to that person everyday, and suddenly stop, I can't handle it. I mean how can I put it :P Like, before my sister got married, I was very close with her. And the first months of her marriage I couldn't sleep, 'cause we used to sleep in one room, I used to cry a lot :p I used to call her everyday, and even sleep in her house on weekends! Until I got used to the fact that she's 'married' now and all. So this all 'what's the use of friends' is just because I'm scared that I'll get hurt if my friends 'move on'. I guess I'm just afraid of losing them, which I cannot possibly handle.