Her reasons for leaving were 'obvious'. = It's 'obvious' why she left.
You are stating 'the obvious'. Tell me something I don't already know.
Her doctor immediately noticed the 'obvious' signs of the disease.
(..) He's a lawyer and I'm his law clerk. A fairly recent appointment, but enjoying it, all the varied work. - A lawyer? - Isn't it obvious? Lady Croft, my pleasure. - Manfred Powell, QC. - Good morning. - I believe you're quite an authority on things Ancient and Mythological. (..)2001 Lara Croft: Tomb Raider