I wasn't suggesting that it's an identical situation to either of those, just that sometimes a player 'clicks' at a club, if you like. Moving away from that club is sometimes a big error, both for the player and the buying manager - to the player, the grass might appear greener and they forget about the other factors that are contributing to their success at the original club. In Carroll's case, those factors were arguably that he'd already convinced our fans he was class, the influence on and off the pitch of Nolan, and the on-pitch service of Barton. And that's before you consider the pressure that a £35m price tag brings, regardless of what he might say about it not fazing him.
fwiw I think Carroll will end up back at NUFC one day. Liverpool and Carroll just feels like an uneasy fit to me.