I think that Simon mis-characterized Matt's issues. Matt knows that he is a damn good singer - his is confident in that and that is why is even there. He knows his own potential. What Matt has been lacking is people around him that believe that singing should be his career. He's probably had people repeatedly tell him to go and find a proper career. He has resisted making that final boring career choice for fear of losing his dream. That is why he keeps ending up in "rubbish jobs." Dead end jobs are easy to get out of. But without people to cheer him on, he has lost the confidence that his preferred career path can ever happen. He knows he can succeed at it, its just that nobody has helped him find his way. But now it seems that he has built the courage up to go for it even if it puts him out on a limb. He desparately wants the chance, but just doesn't know to believe that success is something he deserves.