Another Tale from the Front

So my boss was explaining to Mike (guy who sits next to me) something about "comparing those numbers are like comparing apples to oranges."

I interjected, "Why do we use 'apples and oranges' as a simile for opposites? I mean, they're both round, both fruits, both grow on trees...shouldn't it be more like 'apples and carburators?'"

About an hour later, Temp Boy, out of nowhere turned to me and said, "One is hard and one is soft."

"What?"

"Apples and oranges. You were saying how they are same, but I have difference for you."

I turned to Mike whose face was already red from laughing.

Why me?

Rock On,

Aitch