I Think, Therefore I Am?

One time when I was little, I remember seeing a large billboard in Nashville(?) that read, "I think, therefore...therefore...therefore..." There was a picture of an elderly person with a frustrated, pensive face, his hand on his forehead.  I asked my parents what it meant, and they told me about the old philosophy of Descartes (had to look that up): "I think, therefore I am."  But this billboard was an advertisement for an Alzheimers center, and made its point quite clearly.

Lately I have noticed that I am quiet a lot, and probably look like I'm deep in thought.  But when I think about this, I realize, I'm not.  My mind is pretty much blank a lot it seems, unless something shoves it back into gear in the outside world, temporarily.  I read, and it makes me think while I read, but then, I quit thinking.  Maybe I am afraid that if I start thinking, I will be overwhelmed.  So I just give up for awhile.

Is that weird?