Trips to the beach keep me 'sane'. [=keep me feeling happy and able to deal with life without becoming too upset, nervous, etc.]
It's hard to stay/remain 'sane' [=to stay relaxed, calm, etc.] when I'm so busy.
He is perfectly 'sane'. [=he is not mentally ill]
(..) Pumpkin, that's modern medicine. Advances that keep people alive who should've died a long time ago. Back when they lost what made them people. Your job is to stay sane enough so when someone does come in that you can help, you're not so braindead you can't function. For the love of God, what? (..)2001 TvShow: Scrubs Title: My First Day Season: 1 Episode 1