I get the same vibe too. Even when he was playing for us, I felt there's this cockiness to him. Whether that's good for his long term future remains to be seen. This is no doubt going to sound like I'm bitter over an academy player's departure.
There are moments of him not putting in a defensive shift at Chelsea, which a coach like Poch might turn a blind eye to, but will definitely not fly with Pep. Ironically, he didn't seem to do that when playing for us.
At the end of the day, he got what he wanted, and he's done well for himself. So fair play to him, he's a good footballer.