Blackbelts: did you have a 'fear' of getting your blackbelt?

I have a good friend we'll call John, I met John in a dingy little gym in 2007 and he was already a blue belt teaching classes (the old school Gracie way).

He's about to get his blackbelt in December and he seems to be feeling imposter syndrome. To the point where he's treating December like he's training for the ADCC.

Our coaches and any other higher belt I've ever spoken to about him says he's been a blackbelt for some time and I agree.

Is it normal to feel imposter syndrome for a rank you know you probably deserve?