"Nothing Rhymed(Gilbert O'Sullivan)" A question about this famous song
This song also has bothered me for many years. Especially bellow part:

This feeling inside me could never deny me
The right to be wrong if I choose
...What does it mean?

I have a right to be a wrong person. I can be a wrong person if only I decide to choose. I cannot deny the fact that I'm believing so deep in my heart.
Whatever I choose always turn to be wrong. Although I had believed them as righteous for the first time. And this feeling inside me won't fade away.
...Which is correct? Or are both incorrect? Can someone explain me grammatically?

Question

"Nothing Rhymed(Gilbert O'Sullivan)" A question about this famous song
This song also has bothered me for many years. Especially bellow part:

This feeling inside me could never deny me
The right to be wrong if I choose
...What does it mean?

I have a right to be a wrong person. I can be a wrong person if only I decide to choose. I cannot deny the fact that I'm believing so deep in my heart.
Whatever I choose always turn to be wrong. Although I had believed them as righteous for the first time. And this feeling inside me won't fade away.
...Which is correct? Or are both incorrect? Can someone explain me grammatically?

Answer

I don't know the song but if going on available evidence its probably some sort of love song. 
The lyrics mean that the feeling he has cannot stop (or deny) him from acting as he chooses, even if he knows it might not be a good idea.
For example: you might know it isn't a good idea to date your friend's wife and you have a feeling that tells you this. However that feeling cannot deny/stop you from acting as you want because you and she have fallen in love. 
Hopefully this clarifies it for you.

Answer

I believe he is simply playing with words and rhymes. Bear in mind the title of the song is "Nothing Rhymed." There is a change of key for "This feeling inside me"  the song then goes on to rhyme "choose" with "lose".

Answer

Thank you! That's what I wanted to know.

Answer

He means "the right to decide for himself what to do even if it's the wrong decision".  That is "the right to be wrong".