Everything she says, the way she says it, even the amount of time it takes her to reply to you are all things you can't help but overanalyse and obsess with. Did she mean to graze your hand with hers? What did she mean by that? How come she's smiling at me like that? It's driving you insane to treat everything she says like a cryptic riddle, especially when it's more than likely she never meant anything by it.