Unclear where 'nadster' originates from. Likely related to nads, as in someone who's "got balls", or the Polish 'nad', meaning 'above' - say, 'above keen'.
"Nah, nobody's in there. We'll end up floating around like abandoned toilet paper. Don't want to be super-keen nadsters."
"I looked at the slogan I'd painted up on the banner: 'Come on lads, be a nads(ter)!!'. What was I thinking? The pun didn't even make sense. I looked like such a super-keen nadster."