You're a team player; nothing great has ever been accomplished with just one person. Anyone who says otherwise is probably a not very nice person, and not someone who you feel the need to be associated with. You make friends for life, and you take those relationships very seriously. Like, blood oath seriously.
There is nothing that has been invented that we cannot live without. Because, for something to be invented we've had to not have had it before. People sure would piss and moan though if the car was taken away....to answer your question.
At work, you may think you can't go more than a few hours without food and water. Sitting in a discount office chair in your cubicle is certainly no way to test your limits. There are many factors that go into how long a human can survive without food and water, and the will to do so is one of them. Going without water isn't smart, and it doesn't take long before you're suffering from dehydration. Food is a different story. Humans can go quite a long time without food as long as they're well hydrated. Your body weight, overall health and the weather play into the scenario as well.