Help me in writing a speech on the topic of 'necessity is the mother of invention'.

Throughout history, man has invented things as his need for them arose, and according to his understanding at the time.  As a general rule, most men and women go along in life quite content with the way things are around them, until a situation comes along that provides a stumbling block (so to speak) to their forward progress.  For example, a large rock rolls down the mountain and onto the road, blocking the highway and making everyone have to detour around it.  The masses come and go until, invariably, someone eventually comes along who looks at the rock in his way, wants to remove it, figures out how to do it with tools and dynamite, blasts it away, then restores the road to its original condition and goes merrily on his way.  Such is and always has been man's great ability to adapt, invent, and improve.  This, I think, is the message behind the saying, "Necessity is the Mother of invention."