Who can explain the deep meaning of these words in Cao Cao's short songs?

These four sentences are about the scenery in front of us, that is, the scene is full of emotion, from birds choosing wood to living, thinking that talented people choose their masters, and hoping that talented people will come back and make achievements. The comparison of the last two sentences shows that the more talents you accept, the better.

Judging from the content, this poem was probably written after Battle of Red Cliffs. At that time, due to Cao Cao's military defeat, the cause of reunification was seriously hindered. Therefore, I feel that the years are fleeting and my ambition is hard to pay, and I have sighed' the geometry of life' and' how hard it is to go to Japan'. But what he will never forget is the cause of reunifying China. He quoted the poems of Kiko and Luming Literature to express his admiration for talents. Finally, compared with the Duke of Zhou, he expressed his desire to recruit talents and make the world return to the heart.