I think taking on challenges is what he loves, but there are a few issues with this; he's now been able to buy VVD and AB. He's seen what buying at the top table has done for his team and his job, and he probably doesn't fancy phoning up Caulker to see if fancies another dalliance.
I don't think it was fantasy land that Klopp may have extended here again for another couple of years depending on his health, his family, and the team, but we're taking away that option as why would he want to stay here?
Finally, when he signed his contract, he said it was important because players wanted to know what his future was before signing, so it's clear he wasn't talking about a backup left back from the greek league, and now he sees all of our rivals signing the players he wanted, despite signing a contract, and those other clubs working in the same league as us.