For the modern person living in an industrialized society, going a few hours without electricity is a scary thought. If the power goes out, we're on the phone to the electric company almost immediately, asking when it will be back on. We rely on it to see in the dark, to keep warm when its cold and cool when it's hot. Some people would die very quickly without it (such as premies in incubators and people with pacemakers). Most people use electricity or at least benefit indirectly from some product of it 24 hours a day.Yet it is quite true that there was a time when people did not know how to harness the power of electron flow. It has long been held that Benjamin Franklin was the first to truly harness electricity. However, some historians argue that even the ancients knew about electricity (citing the "Baghdad Battery" as an example). Still it is clear that large scale dependence on electricity for daily life didn't begin until after Franklin.
Up until the 1860's, the term "plastic" simply meant something that could be given various shapes that it would then retain. It also meant someone who's ideas were easily influenced. If you had told someone prior to the 1860's that you had made something out of plastic, it wouldn't have made sense to them.
Today however, it's getting harder and harder to find something that is not made from some kind of plastic. Imagine what your surroundings would look like if suddenly all the plastic in the items you see was to vanish! You' likely have nothing but piles of screws, wires and various other little bits lying around. The Internet connecting device you are reading this sentence on wouldn't even exist without plastic.As far as I know, the inventor of plastic was Alexander Parkes who demonstrated it at the Great International Exhibition of London in 1862.
Since almost the dawn of history, we have been using the wheel in some form or another. It's been so long since it was invented, that no one knows for sure who the inventor was. However, since one cannot simply grow wheels right out of the ground nor hunt them down like animals, someone had to have invented them. Many historians think that the wheel must have been invented in somewhere in Eurasia since use of it was so much more prevalent and advanced there than it was in the Americas, even by the time that Europeans "discovered" the New World.Most people today wouldn't think of traveling further than a few city blocks without the help of wheels in some way (whether that be bicycle, car, motorcycle, bus etc.) Wheels are also the main form of the gears and pulley systems that allow so many devices to move. Even the CD/DVD tray of you computer wouldn't open without wheels.
We would have only a vague idea of what time it was without clocks. You can kind of guess what time it is by looking at shadows and positions of the sun and moon, but our fast paced modern life requires more accurate measurements than that. Besides the obvious examples of wall clocks and watches (itself a relatively recent invention), you'd be amazed at what else in your life has clocks in it. These include: your TV, computer, cell phone, microwave, electric stove, stoplights, etc.This is another of those inventions that occurred in so many places at roughly the same time and so long ago that we aren't sure who first invented them, but the clock as we now know it didn't gain widespread use until after the 1500's. Even then, they were not in the private possession of the "common man" until after the Industrial Revolution.