"Not the fish! I cannot believe how everyone seems to be convinced it’s that. Nemo, which is Latin for "nobody," has nothing to do with the Disney film. It revolves around the feelings I have from time to time. I feel nameless and do not know who I am or where I will go. I only know my past and I long to be back there. The song is about being lost, not knowing where to go or what to do, yet desperate for everything in life. That’s not always me, but when I wrote Nemo, that’s the way I felt. Now I feel better." (Translated from the German)
Straight from the songwriter's own mouth:
"Not the fish! I cannot believe how everyone seems to be convinced it’s that. Nemo, which is Latin for "nobody," has nothing to do with the Disney film. It revolves around the feelings I have from time to time. I feel nameless and do not know who I am or where I will go. I only know my past and I long to be back there. The song is about being lost, not knowing where to go or what to do, yet desperate for everything in life. That’s not always me, but when I wrote Nemo, that’s the way I felt. Now I feel better." (Translated from the German)
–Tuomas Holopainen, Underground Empire interview