It's a word I've used all my life without really thinking about what it means, but all the time knowing what it means without thinking about it.

Dictionary:

"A series of pleasant thoughts that distract one's attention from the present."

Would ADA and mindfulness techniques be:

"A series of pleasant thoughts that direct one's attention into the present"?

From Wikipedia:

...a short-term detachment from one's immediate surroundings, during which a person's contact with reality is blurred and partially substituted by a visionary fantasy, especially one of happy, pleasant thoughts, hopes or ambitions...

What would it be to remove all the visionary elements of daydreams? Would it still be a daydream? How can you dream without visuals, and take it one step further maybe and remove the sense of hearing (or more senses)? Can you daydream that you are hungry? Can you daydream that you're more tired than you really are, or more relaxed?