Well he was nowhere near this level at WC. Can't say I've seen him elsewhere though. Certainly not Chelsea
That is true, but at Chelsea, he didn't get much chances, Mourinho didn't believe in him, he said that De Bruyne wasn't showing enough in practice.
He should have known, at Genk this was already the case, but once on the field, he just is great.
Regarding the NT, except for Origi, no attacking player from Belgium was good, they were all nervous, mainly due to the too high expectations they put on theirselfs. In the qualification matches for the WC, De Bruyne showed his value.