LOL very good.
I am a twin and apparently I was like this with my brother when we were babies. We would be speaking gibberish yet we'd still be able to completely understand what we were saying to each other. I think it's because being a twin means the two of you are in your own little world and you seem to develop ways of communicating that are totally unaffected by external rules because you don't need to learn those rules to communicate, and so both understand it all completely. I find it very strange I must say!