Wanting something until you can't have it

We all know it, right?
There's something you don't really care for, but once you can't have it, you suddenly miss it. Maybe you got used to it, maybe you always kind of wanted it but thought you didn't.
It's like having that one friend you thought would always be your friend and suddenly one day you realise they're not your friend anymore. When you think about it, you didn't have all that much fun together, but now that you don't hang out, you miss it and you really wish you could just call them and that things would be like before.