I'm INTP and my girlfriend is INTJ. I consider myself very lucky to have someone to relate to. We have a lot of the same habits -- e.g. we both stay up too late, are too stubborn, and we try to be completely honest with each other -- and usually this is nice, but sometimes we get carried away.

For example, when we met four months ago, we almost completely ignored our school work in favor of getting to know each other.

And for the past week we've been going to bed at 5am and waking up at noon. Ugh. :)