What's in a name?

So as of yesterday the boys can say each others' names. And it is the most precious thing I have ever heard. I was dressing them for bed and they sometimes like to be put in one crib together to play while I read them a story. Logan was fussing for Jack and I said, "Tell Mommy what you want." And he signed & voiced "Jack". It sounds like "Dat", sometimes "Dack". So cute!
Then once Logan was in his jammies in his crib, I was changing Jack. I asked Jack, "Do you want to go in Logan's crib?"
And he signed & voiced "Logan". It sounds like "Nin." I feel like I have been waiting forever for them to ask for each other. Now they can. And it warms my heart!