This poem expresses a belief and contains a philosophy. The poet compares the ideal to the sea, the difficulty to the mountain, the difficulty to the mountain climbing, and the arduous struggle to the mountain climbing, thus telling people that the road to the ideal is long and rugged, and to reach the ideal state, we must be fearless.
The sea symbolizes the goal to be pursued. Everyone has his own pursuit, and everyone should pursue it unremittingly. With firm faith, people will always achieve their goals.