First of all, I wanna say thanks to all the people who replied to me. I often feel that every step of connection towards people will upset them, and that I will make people mad with me or something. Your answers make me feel a minimum of social connectedness and it feels so good. Thank you all.
Music will almost automatically trigger me to switch into the daydreaming state, so to say. But there was a time I tried to cease the daydreaming completely, and after months of hard trying & failing, it worked out and I was even able to listen to music without daydreaming. And even than it lifted my mood.
I guess I don't have to mention that I finally ended up daydreaming again, but even though it's maladaptive in some way, looking back to the no-daydreams phase of my life, I'm glad I have this coping skill- it's just I wish I had a little more control over it. I will do compulsive movements during daydreaming, especially rocking back and forth (sounds pretty psycho I know), and this is causing me back ache. It's not a serious medical thing or something though.
Besides of that, my daydreams are often accompanied or alternated by some kind of real intense, trance like mind wandering. During this, I often have spiritual/philosphical epiphanies or ideas. I enjoy this very much. And yes, of course I hope to make some of my dreams become true some day.
With regards to the zoning out thing, I do the staring thing as well. This happens especially during phases of heavy depression. Strangely, I sometimes stop breathing as well, and I only realise when I start feeling giddy and than I will kind of snap for fresh air. Don't know. I didn't think about that before.