People who walk on a moving walkay are faster than people just walking. If you add another speed to the speed, the overall speed get increased as much as you add.
But the case of light is different. Light can't get faster. Light is always 300,000 kilometers per second under any circumstances.
The speed of light from the car stop is 300,000 kilometers per second. The speed of light from the car going with 300 kilometers per hour is same, 300,000 kilometers per second.
The speed of light never changes. This is called the principle of constant light speed.
Here comes Albert Einstein, the super hero of physics. He thought the speed was the same, and he thought that time and space could be different. The time of a fast-moving object (human) flows slowly and the space decreases.
Everybody has different time and space. They're relative to each other. However, many people believe only their senses and experiences without acknowledging the differences they cannot feel.
We must fully understand that each other's time and space and the world are different. Especially, leaders who lead everyone should know that they are different from the relativity of the world. Because they get the responsibility of the guiding to everyone's good lives.