I don't know if this counts, but as a kid I had very vivid dreams where I could breath underwater. I had the same dream a few times a week until I was 10 or 11. I was swimming in a pool of water, it was very warm and comfortable, and I could move around and breath in the water. Sometimes I dreamed that I couldn't see, other times, I could see but that everything was kind of blurry. It was just a really pleasant dream, but I remember worrying that I would get into a swimming pool and forget that I couldn't *really* breath, lol.
I always just assumed that I was somehow remembering what it was like before I was born. But, I suppose it could also have been a subconscious desire to be a fish, lol.
