Let's explore the objective/subjective realm in lyric writing.  This can also be called  stimulus/response technique.

Put the two concepts together and you get "objective stimulus" and "subjective response" lyric writing in a song.

Here is an example of a great standard tune using this technique, "I Thought About You" by Jimmy Van Heusen music and 

the great Johnny Mercer lyrics.

First sentence stimulus - I took a trip on a train -  objective 

Second sentence  response - and I thought about you - subjective 

First sentence stimulus - I passed a shadowy lane - objective 

Second sentence response - and I thought about you - subjective 

First sentence stimulus - Two or three cars parked under the stars, a winding stream,- moon shining down on some little town and with each beam

At the end of the first sentence he inserts a three word  response - same old dream -  subjective

This song alternates between objective/subjective, stimulus/response and is a beautifully written lyric.

Take a look a the rest of the lyric and you will see this structure.  The interplay between these two planes "objective/subjective" makes for a very rich dynamic in lyric writing.