There is as story about four engineers in a car that won't start.
The mechanical engineer says, "Let's strip it down and rebuild it.
The chemical engineer says, "It's the fuel, we should empty the tank and refill it with fresh petrol."
The electrical engineer says, "I think we should check the plugs and make sure we are getting a spark."
Finally, they notice that the computer engineer hasn't offered an opinion. "What do you think?" one of them asks.
He replied, "Why don't we all get out and then get back in again and see if that makes any difference?"
The mechanical engineer says, "Let's strip it down and rebuild it.
The chemical engineer says, "It's the fuel, we should empty the tank and refill it with fresh petrol."
The electrical engineer says, "I think we should check the plugs and make sure we are getting a spark."
Finally, they notice that the computer engineer hasn't offered an opinion. "What do you think?" one of them asks.
He replied, "Why don't we all get out and then get back in again and see if that makes any difference?"