To win multiple Slams past age 30 today, you HAVE to be either a Federer or a Nadal - meaning either oozing with talent or built like a tank with one lethal weapon. Djokovic is neither - not even close.
He may have come up for air one last time just like Sampras did for his No. 14 'emboldened' by having missed 'immortality' due to marital problems AND fascinated by the magical run both Nadal and Federer have been on this late in their careers.
Even though defeating 'in full flight' Nadal is a worthy achievement, you cannot ignore following facts:
-It was in VERY close FIVE sets - over two days.
-It was on grass - where Nadal had done JACK for decades.
-Nadal was coming off a grueling clay season where he won everything short of Diana Federer.
-There's NO freaking question that five setter took something significant out of Djokovic - physically - specially when you insert No. 31 AND his past marathon matches against Nadal as a contributing factor in Djokovic's rapid physical degradation.
Granted above may neutralize when you factor in where Djokovic was coming from but when you extrapolate Djokovic's showing beyond Wimbledon onto other Slams above factors may become relevant.