There are lots of kinds of evidence. I'd be curious to know how you define "scientific evidence." I'm not a scientist. I use a variety of critical thinking tools to weigh and evaluate evidence. I don't struggle with the existence of dreams.
I found an interesting article about a woman who stopped dreaming after she had a stroke.
http://news.bbc.co.uk/2/hi/health/3645576.stm
As to your question about my kids:
Have you always taught your child(ren) the truth about Santa Claus (for example)?
I'm not Christian. I've never lied to my kids about Santa.
As a young parent, I was not as conscious about what I was doing as I wish I had been. I would parent differently now. I asked my son (18 years old) whether I had lied to him about the tooth fairy. He couldn't recall ever believing in the tooth fairy. Maybe I told him the truth. I'm not sure. It's possible that I was not honest with my daughter (now age 21) about that. If so, I regret my dishonesty.
Your questions prompted both me and my son to remember a lie that I told when the kids were little that I also regret. My daughter refused to eat fish. I told her that the meat the I was serving for dinner was "steak." It was a salmon steak. She ate it, said it was good, and then I told her what it was. Many years later, my lie must still hurt her. She still talks about it. Also, she doesn't eat fish.
Shelley