Actually, there are a lot of things running through my mind.
But because it's a lot, and it's running, I never do realise what am I or have I been thinking about cause I never get to catch them. Until my thoughts get tired of running, they slow down, then they stop, then it probably means I'm no longer thinking about it.

So at the end of the day, I realise that..
I'll never get to know what am I thinking.

My thoughts just wasted their time running.