You asked me last night what I was thinking about
Which made me think about what I was thinking about
Which made me think about you thinking about what I was thinking about
Which made me think about why you were thinking about what I was thinking about
Which made me think about what you could have been thinking about to make you wonder what I was thinking about
Which made me wonder what you thought I was thinking about
Which made me think about what you were thinking about
& while I was thinking about all of this, I realized that the answer to your question was, & had been the whole time:
You.