Why do some people space out so often? And why is this interpreted as sadness?

Tend to space out often myself, usually getting caught up in an idea or drifting off into my own world where the struggles are less. Also been told I look sad when it happens, believe it's because those thoughts would seem like a better reality to me, yet we cannot have it, which is making me sad. Though, it's probably very different for everyone :)

Why do some people space out so often ? It is said that people tend to zone out when they want to escape or disassociate from their lives. We all tend to do so when we're bored or we just don't want to be where were are. Those that do it often it's associated as sadness because our doing so when we're bored tends to be unintentional. The mind that zones out often, becomes a protective measure that there is something that the mind is wanting to hide itself from. Something that is painful that we leave the painful space for refuge.