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.
Generally speaking, people can only survive about a week without water. However, a lot depends on the weather conditions, your level of body fat and your general health status. Being in hot climates, being obese or sick can reduce the amount of time you can survive without water. Video of the Day