Go over something in your mind - Idioms by The Free Dictionary
go over something in your mind
go over (something) in (one's) mind
To think about something, perhaps to understand or make sense of it. I've been going over our exchange in my mind, and I still don't know what I said to upset her so much.
go over something in your ˈmind think very carefully about something that happened to you: I go over that terrible moment in my mind every day.