The real lyrics:
I can't preach but I can sing

But I misheard them as:
I'm a freak and I can't sing

The embarrassing moment of revelation:
I went up to Martin Smith at a signing and told him he shouldn't put himself down. He told me the real words.

Age when I realized how wrong I had been:
26

Misheard by:
Jon Poutes

I have managed to convince others that my version is correct: yes
I think my version is better than the original: yes

................................................................................

The real lyrics:
And me and my brothers here, are gonna play redemption hymns

But I misheard them as:
And me and my brothers here, are gonna play redemption games

The embarrassing moment of revelation:
My friend laughing at me and correcting me

Age when I realized how wrong I had been:
15

Misheard by:
Paul Musgrave

I think my version is better than the original: yes
I am on special medication: yes