Who´s thinking?

When I walked in the small forest today, on my way home from dads, I let my mind “free”.
It is strange because when I do that, when I don´t really “think” about something. Thoughts just pops up, more or less randomly. Sometimes I wonder, who is thinking those thoughts? Those thoughts don´t seem to be connected to me. Is it just something the mind does when it has nothing better to do?

Happens a lot nowadays.