When you find someone who makes you happy, and your love for them glows golden and keeps you separate from the rest of the world, it's quite natural that you should want to shout it from the rooftops. Indeed, just about the only thing you want to do when you're in love is tell everyone in earshot every detail about the perfectness of your union. The small problem with wanting to do this, however, is that there is no one - not even your closest friends - who really wants to hear that shit.
If you do choose to tell them, they'll pretend to listen, of course. They'll nod and smile, and say something like, "I'm so happy for you!" while they're putting together to-do lists in their head. But they don't really care. And they certainly don't really understand. So, you bite your tongue hard and keep it to yourself, even though it's probably all you can think of.
And this is why lovers never run out of things to talk about.