Newton's Third Law Explains Momentum

If space is the same everywhere, then you're not going to automatically lose any energy or anything by moving to a different spot in space. If there's something else acting on you, Newton's third law comes into play and says for every force, there's an equal and opposite force in the other direction. So it kind of works like that, that you don't just spontaneously lose momentum. If you're going to lose momentum, you have to give it to something else. And essentially you can think of it kind of intuitively.