Lyric discussion by stanlavisbad2 

Cover art for There She Goes, My Beautiful World lyrics by Nick Cave and the Bad Seeds

I don't think it's so much about losing the muse, more to do with wanting someone to be his muse, but she isn't. The lines:

I look at you and you look at me and deep in our hearts know it That you weren't much of a muse, but then I weren't much of a poet

indicate that to me. Also, he is willing to do anything to have that muse, as he says in the verses " i will lie at your feet" etc. It's a song about envy of the great artists, and also about desire to be one of those great people, but the realisation that he is not really good enough.