Lyric discussion by drew4355 

Cover art for Mr. Soul lyrics by Buffalo Springfield

Young is talking to his soul to help prevent his ego getting the best of him because of his fame, which he seems to be amazed at. He was ready to accept the fame when a fan brought him down to earth.

This conflict between his soul and ego made him depressed, but he was lifted by a fan letter. A fan who did not know him personally, told him she loved his eccentricities. She told him not to change but the letter pumped up his ego more.

He is afraid his phony happy persona will turn him into a caricature. He is telling the world he is a troubled soul who will self destruct. He is quickly getting caught in the fame and ego thing that he is leaving his soul behind. The last line seems to say that the fan knows him better than himself.

My Interpretation

@drew4355 -- My gosh, I think you've deciphered this one! Pretty close, anyways.