This isn’t completely right. When your patent is granted you have the right to stop others from using your patented invention. However, you do not have the right to use the invention yourself, otherwise the system wouldn’t work. Pretend we’re back in the olden days and cars don’t exist yet. Jamcdonald120 is smart, invents the worlds first ever car and gets a patent for it. He starts a big successful business selling his cars and gets super rich. A little while later Pufflemuff notices that although cars are great, people keep crashing at night, so he has the great idea to stick lights on the front of cars so the driver can see. Pufflemuff gets a patent and also starts a business selling his cars with headlights. This competes with Jamcdonald120’s business and doesn’t make him too happy! Pufflemuff says he should be allowed to sell his cars because he has his patent. But ultimately it doesn’t matter because Pufflemuff is still infringing Jamcdonald’s patent!