Necessity is the Mother of Invention

I think the quote "Necessity is the Mother of Invention," means that whatever you want to create, needs the right supplies. If you have the right materials, then they will give birth to the invention. I think people invent things because they want their life to be easier. For example, people could have sent messages to one and other by horses, but then somebody invented the telephone, because they wanted sending messages to be easier.

Image from: http://www.flickr.com/photos/25452104@N04/2404258455/