It is possible that it could be about Terra. Riku had friends but where there was Terra there was hatred. Terra was consumed by darkness and there was no one there to friend him or be with him (unlike everyone else INCLUDING Riku) despite how he seems. Also he ventus and aqua all grew. The only problem with this theory is the fact that is says "It was all real and i never knew it" which goes with very few to none of the characters.
It is possible that it could be about Terra. Riku had friends but where there was Terra there was hatred. Terra was consumed by darkness and there was no one there to friend him or be with him (unlike everyone else INCLUDING Riku) despite how he seems. Also he ventus and aqua all grew. The only problem with this theory is the fact that is says "It was all real and i never knew it" which goes with very few to none of the characters.