Although I don't think my normal studies go deeply into the realms of sleepwalking (also known as Somnambulism), I found some time over the last few days to do some research for the benefit of Alice. I wasn't able to find many exact descriptions of what one does while sleepwalking, but I have found three key facts which may or may not lead to an answer.
1.) Sleepwalking is thought to be genetic; if your parents sleepwalked then it is likely you would as well.
2.) It is also linked to various disorders; I wasn't able to find Schizophrenia among them but it's very possible that the disorder was a link in the chain. It may have even strengthened it.
3.) People who sleepwalk do not usually remember it. Which explains just why one wouldn't remember writing the Morse Code down, and even more so the actions done while sleepwalking are said to be rather odd. I'm sure this varies amongst the people, and the person who spends less time outside will have less episodes of going outside than a person who does spend a lot of time outside.
Before I simply leave this off there, I decided to go a little bit into the odder realms of dreams. I wanted to find a meaning to the Morse Code being written. I don't normally trust this stuff, but maybe your memory will be jogged, right Alice? It certainty couldn't hurt to post some explanations of what the dream may have been, and will at least give a good laugh.
Trees: I found various things on specific trees, but I took it to mean a generic tree. Like a forest, so I followed a generic description. It was, among other things; new hopes, desires, dreams, knowledge, protection, and stability. As a side note, as I think it's worth mentioning, if there were crows in the trees, it represents death. Such a grim outlook on a beautiful bird, another reason why I really can't take these things seriously.
Morse Code: It seems that something in your dream while you sleep walked showed that you had to express something. Or something was hidden, and you had to quickly figure it out. I admit this doesn't fit with the trees, and as I can't look up 'SEEYOU', I'm not sure what to make of the Morse Code other than it being a side effect of your sleepwalking.
Eyes: I had trouble trying to find ones for Eyes, as it's the closest I can come to 'SEEYOU'. Everything I found was about the eyes being closed, but since they were obviously open, I'm going to put down the opposite of what it says. It means to accept the truth of something, which in a way conflicts with the Morse Code altogether.
It's.........interesting. I don't remember the source sites, but I used at least three of them, they all basically told the same things.