Lyric discussion by PaulPavlofski 

Cover art for I'm The Urban Spaceman lyrics by Bonzo Dog Doo Dah Band, The

I think there's some lyrics about taking drugs, more specifically amphetamine.

I don't think that's the main topic of the song though, I take it to be about media portrayals of people resulting in unrealistic expectations of humans in general.

It talks about being a glossy magazine, and an advert but ends with saying these people don't really exist.

My Interpretation