Necessity is the mother of invention

I think the saying necessity is the mother of invention means that when something is needed it is created or invented. Take the light bulb. Before Thomas Edison invented the light bulb there was a great need for it. People could only work with a oil lamp which generated heat and smoke and required you to fill it with oil. This was too inconvenient and there was a NECESSITY for a new INVENTION. Thus this necessity caused or mothered the new invention. Now lets face it, human are never happy with what they have and then these necessities turn into luxuries. But what ever these level of the necessity may be, it always leads to inventions!sd!