Today I noticed that the diffuser in the ceiling had an interesting play of light and shadow on it.  The appearance was Salvador Dali esque and made me think of wrinkles in the time and space continuum.  This led me to consider how my perspective is influenced by factors within and without my control.  And then I tried to focus on my breathing and stop thinking so much.  It is also probably not a great idea to mentally write to do lists during yoga.
In case you are not familiar with one, here is a picture of a diffuser.  Sadly it does not have the light and shadow play.  Please imagine that part.

And my yoga instructor wants to write a book with the title of this post.  Watch for it!