What does "Fortunately, I sing to express my ambition" mean?

Translation: Ah, I am so lucky and wonderful. Let us sing to our heart’s content and express our feelings freely.

From "Viewing the Sea" by Cao Cao of the Han Dynasty, the original text is as follows:

To the east is the Jieshi to view the sea.

Where is the water? The mountains and islands are standing tall.

There are many trees and lush grass.

The autumn wind is bleak and the waves are rising.

The journey of the sun and the moon, if it comes out of it.

The stars are as brilliant as if they came from within.

Fortunately, I sing to express my ambition.

Translation:

Go east and climb Jieshi Mountain to enjoy the wonders of the sea. The sea is turbulent, and mountains and islands are lined up in the sea, towering upright.

I stood on the top of the mountain, and the waves in my heart were undulating like ocean waves. Surrounded by lush trees, lush flowers and plants, it is peaceful and seems to be meditating.

The bleak wind came, the vegetation was shaking, and huge waves were rising on the sea, rolling and roaring, as if they were about to engulf the universe.

The sea, what a broad mind, the rise and fall of the sun and the moon seem to come from the breast of the sea;

The brilliant stars in the Milky Way also seem to emerge from the embrace of the sea. .

Ah, I am so lucky and wonderful. Let us sing to our heart’s content and express our feelings freely.

Extended information

Appreciation

This poem was sketched by Cao Cao with a brush full of romantic passion when he was climbing the Jieshi Mountain and looking at the sea. The sea swallows up the sun and the moon, and contains thousands of magnificent scenes; it depicts the majesty of the motherland's rivers and mountains. It not only depicts the magnificence of the mountains and the sea, but also expresses the poet's enterprising spirit of using the scenery to support his aspirations and have the world in mind. The whole poem has simple language, rich imagination, majestic momentum, desolation and solemnity.