Thinking can be a terrible thing. WHAT? How can thinking be a terrible thing?
I'll tell you provided you are open to possiblities....

Because my mind doesn't shut off very well I stay up late at night and get up early in the morning. That was fine when I was 20. But now i think a lot. It just adds extra stress during the day. Insomnia caused this post as it caused most of my more.. oh how we would I put it.. thought provoking posts?
Thinking can be a dangerous and terrible thing (getting back to the post at hand)
Thinking brough about swords and knives; guns and bombs. Think brought us into a age where there are weapons that can destroy millions upon million of lives with the press of a button.
It is said the most dangerous weapon the military ever had was the imagination of the 18 year old soldier....
I could list other examples but I won't....

The mind is like parachute. It only works when open.
Now imagine you need to use that parachute as a pillow... it won't work unless it's closed. now.. where does that leave the mind?

Think about it....