Ronaldo helped Juve to their eighth Serie A title in a row but they fell short in the Champions League after being dumped out by Ajax in the quarter-final.
The former Real Madrid star took the brunt of the criticism as he was brought in with European success in mind.
Ronaldo has scored 28 goals in all competitions this season and can still improve on his tally with three games of the season still to play.
However, the 34-year-old admits the constant need to prove himself is beginning to take its toll.
“I won’t deny that sometimes I get annoyed and tired because it seems as though every year I have to prove that I’m very good,” he said in an interview with ICON magazine.
“It’s difficult, you have extra pressure of having to prove something to people and it’s not only for you, but your mother, your son.
“It makes you more active. You have to train, but there comes a time when you have to say ‘look, let me be’.”
Despite that, Ronaldo insists he is happy at Juventus and is pleased to have adapted well to life in Italy.
“You have to be humble,” the five-time Ballon d’Or winner said.
“You have to learn that you don’t know everything and, if you’re smart, you improve little things that make you better as an athlete.
“I’ve adapted perfectly at Juventus. They saw that I’m not a smoke seller.
“They saw that I’m Cristiano Ronaldo and that I am what I am because I take care of myself.
“Why have I won five Ballon d’Ors and five Champions Leagues?
“People are always judging. They said ‘it’s over already, he’s 33, 34 or 35 years of age’.
“You want to surprise people. They see me a person who can never have a problem.
“They see me as someone who can never be sad and never have worries because of my success and money. You have to understand that people don’t think like you.
“I understand that and know that people are waiting with a shotgun for me to miss a penalty or fail in a big match.
“It’s a big part of life and I have to be prepared, which I have been for many years now.”