Position is a relative measurement. If you want to know how far away in object is you need to know where you're measuring from. That is, distance always requires two points. Velocity is the time rate of change of position. If position is a relative measurement then so must be its rate of change. This means the statement I am moving is meaningless. It is not a meaningful thing to say that and object is moving without saying what it is moving with respect to. As an example imagine getting up and walking around on an airplane while it is in flight. you do not have to run 600 mph to get to the front of the plane you can simply walk around just like you're on the ground. That is because in your frame of reference the plane is not moving at all. It is the earth below that is moving. But the people on the ground think the plane is moving in the earth is at rest. Both people are correct because each observer has their own frame of reference. The only universally true statement is that there is relative motion between the plane and the ground. Every observer can agree on the fact but they will disagree on the speed of the earth and the plane. That is because motion is a relative measurement. In a similar way if someone asked how far away is Paris? Your answer would be different than mine because we live in two different locations. Neither of us are wrong but that is because Paris is not a definite distance away from every point in the universe. That is a commonsense thing for everyone, but for some reason it's easier to get mixed up about velocity. We get used to thinking that the earth is somehow stationary.
