They wanted to help each other, but this made both of them couldn’t move on!
There are two friends who wanted to climb up the wall.
However, when one man helped the other to get up on the wall, he himself couldn’t get up by himself.
So, the other man went down to help the man to climb up successfully.
This process repeated for a few times, yet only one of them could get up on the wall.
I guess they would never get up on the wall to continue their next actions.