My second theory is that this is a song about politics, about a man with radical political views who was all about fighting the system and absolutely certain that one person could make a difference, but started to realize as he got older that he alone could not make a difference so he gave up fighting and drifted away from those political views. Then in the end he realizes that even though he won't be able to change anything that he still deep down holds the same political views that he did when he was young even though he is no longer voicing them.