Another saying I was fond of when I was at Whirlpool. Was talking with an engineer today who was not offended by my statement... he definitely earns my respect for getting it.
Technology is easy. It's black and white. It works or it doesn't.
Products and services are hard. It's grey. Fuzzy. Hard to quantify (if you can at all).
That's why I like Product Management. It's a game. A fun one. Challenging too. You know when you win. But you don't know why.