Yes, it wasn't a whole season. Djokovic couldn't sustain that form.
But look at it on its own: 8 months, 10 titles, 3 grand slams, 5 masters, only 2 losses. Are you honestly telling me you don't find that impressive?
As a season, it was very good, but since we all have seen better in our lifetime, some restraint would be appreciated.
J Mac said Sampras told him Novak had the best season in the modern era.