This is almost OK. Wait until you have twin boys, like me. They are 20 months now, grown at home, no day care ( KiTa as in Germany ;Kindergarden is later on).
They don't speak, but very few words with a meaning ( mama, papa, apa ). But! Here it comes: they speak between them and communicate using a almost invented language. The language is so strange, because is based on using the same word ( twin 1 uses 'bahdi', twin 2 'budji' - approx phonetic rendering), repeatedly but changing tonality, like in cantonese. It's really amazing to see how they can talk each other and coordinate while playing for hours using this language, me and my wife feel we are completly left out :).
In the 80s there was a group of Russian girls (almost identical, sisters or cousins) that spoke to each other in a strange language. They didn't responded if someone spoke to them in English.
It turned out they spoke Russian, but the words and pronunciation young kids use at home is very different to what they teach as Russian in America from textbooks and language tapes. It took a native bilingual Russian speaking doctor to figure out that mystery.
Fascinating - do you remember it? (As opposed to being told about it / vague memories-of-memories). Are there any remnants in how you communicate with your twin now?
They don't speak, but very few words with a meaning ( mama, papa, apa ). But! Here it comes: they speak between them and communicate using a almost invented language. The language is so strange, because is based on using the same word ( twin 1 uses 'bahdi', twin 2 'budji' - approx phonetic rendering), repeatedly but changing tonality, like in cantonese. It's really amazing to see how they can talk each other and coordinate while playing for hours using this language, me and my wife feel we are completly left out :).