Not at all.
Not even a little bit. The mind craves purpose.
Some even theorize that the brain doesn't really sleep...it just goes somewhere else.
So, if you lead it somewhere, it is less apt to wander.
I often imagine myself somewhere where I can't move.
In a foxhole pinned down by enemy fire.
Trapped in the rubble of a collapsed building. What have you.
Then I paint a picture of why
I write a story, create characters, etc.
I've always done this, even as a child.
Maybe I'm weird. (Scratch that, I'm definitely weird) but it helps.