Why is the way back up, out of the valley or up the mountain, so much harder and heavier than down. Down almost goes by itself, you don't have to do much for it, when you're not careful it even goes very hard. Climbing up is difficult, there are also numerous obstacles that have to be overcome.
What is the role of gravity? Gravity is the sum of gravitational power, the earth-generated pulling effect on other objects and centrifugal force, the force an object experiences when it rotates with the earth. That sounds heavy, hard and hard to argue with and difficult to get rid of. If you've ever seen a launch of the Apollo missiles in the 70s of the last century, then you know how a lot of power, fuel and sparking is needed to rise apart from Earth.
As an individual, go up the path. It is certainly worth it, perhaps the only of real, lasting value in this earthly life, but it is going to require a lot of energy and perseverance. Fortunately, there are also forces that meet you once you are on your way.
