Why do people measure?

to check the measurement of something or someone. Mainly to know what we have and what we are trading. If you want to go on a road trip you may want to know how far your destination is. That will help determine how long you will spend on the road. You may want to know how much fuel you have in your car and how much fuel you need. If you buy more fuel, you will want to know how much you are buying so that you can work out how much you should pay. And so on.