That call or e-mail from the friend you haven't seen in ages.
That friend who knows you inside and out and who, when you see her again, will seamlessly continue that conversation the two of you started six months ago.
The message that says, "hey, I miss you. Everything is the same and everything is different. Wish we lived closer so we could have coffee today" without ever really saying any of those words.
The message that makes you laugh and feel like you've gotten a hug and that someone thinks you are special, all at the same time.
But getting that call or that message at just the right time on a day when you really need it? That's some sort of magic.
I don't know how it works, but I'm so glad it does.