Mental block?

I don't know why it seems that my brain is not functioning well today no matter how I try.  It's like my mind is wandering off somewhere, my focus is so poor today.  Do you experience this sometimes?  I do, but not often.  That's why when i am in the mood to write, i write, write and write until my brain stops working.  Do you ever wonder how mysteriously our body work; how each part of the body - from the tiniest part - contributes to how the whole body works.  Each time one part doesn't work well, everything is being affected.  I learned this in  the "Body" exhibit hubby and I saw when we went to Las Vegas last June.  Our body is like a machine that works faster than any computer in the world.  That's why we should take care of our body because this is the only one we got.  I guess while i start this post with a mental block, it seems to be working fine now, lol!  Guess, i just need a little push!