it's cool when....
1) other people use the same inside jokes as you. but you don't know them. ie. someone's blog is "just a lie you've got to rise above", which is a john mayer lyric...just like mine....(ok, maybe not a joke, but you know what I mean?)
2) you wake up to someone hugging you, and then you realize that even though you've slept perhaps too long, it's been a good, deep sleep, and you aren't tired anymore.
3) people from your dts appear in your dreams....in which they are in your city, and you say hi, and it's so good...but then you get woken up (see no.2), which kind of sucks, but at the same time, it's alright.