Two men enter a wilderness trail side by side and before long, they come to a stick blocking the path. One man looks to the other and says we have to move this stick, the other says, the path is long and we are only part way up.
The second man steps over the stick and continues.
The first man stays to struggle with the stick and finds out it is a vine that is tangled in many places and eventually he gets it out, though he is scratched and bruised and covered in debris.

As he goes along the path he never sees the other man again.

The man who stepped over that stick eventually comes to other obstacles each greater than the one before. eventually he wishes he had a hand to get past some of the obstacles.eventually he makes it to the end of the trail. There is a tractor there with the keys in the ignition and a sign that says "now that you have made it, you can help those that come behind you."

When I get to the tractor, will I care for those that come behind enough to go back and help them?