Ed knows automail. Not in the sense that he can make one, take it apart and put it back together, but in the way of how it feels when attached to you. Metal on skin and nerve on wire.

Cold on warm and warm on cold.

He appreciates it the way a starving man appreciates food with its best before date far behind it, not caring for the taste but still loving the way it goes down the throat, filling up the belly. It may taste like shit but as long as it's something, it'll always be better than going without.

Having a limb is always better than having none, fake or not.

Even more so when lacking two.

Winry doesn't really get it, and probably, hopefully, she never will. Because for all the metal she's worked with, every screw and plate and orb, she's never known just how utterly and completely cold it is when it's stuck to you. On you. With you. A part of you.

Ed knows. Knows it like the back of his left hand and knows it better than the back of his missing right. Metal on flesh and flesh on metal.

Fake on real and real on fake.

Cold.