An onion can look fresh. It can feel crisp, and the skin can look great. It might be firm to the touch. It might even smell fresh
Until you start peeking away the layers and realise it's fucking rotten and only worth the bin.
My wife's AP was younger, fitter, thinner, more handsome, funnier, more successful. But he was rotten. He looked good, but peel away the surface and the true nature was revealed.