Life is like a river with a source and a mouth. Each of us has our own river. One person may have one that is twisting and serpentine, with shallow water in the shoals, so one must plod, not float. Another's is stormy, seething, carrying water furiously, flying one hundred thousand miles until it meets another river and loses its impetuosity and noisiness, and then calmly moves forward to the mouth. There are also streams, short and transparent, like the life of a baby.

The old man was plodding along.

Every day Tom plods into work.