The Dutchman is the Reds' third top scorer this season with seven goals, but has still come in for some stick.
He told LFC Magazine: "When you are a player at a club like Liverpool, you have to realise that people expect a lot of you.
"People are always watching you. If you do good things, the papers are full of you. If you miss a few chances or don't play well, the papers are also full of you.
"It works both ways, that's the way football is. I don't mind too much. Okay, it's not a lot of fun to read the papers the next day if they are singling you out.
"But after the Blackburn game, maybe I was more disappointed than anyone.
"I know I work hard enough to start getting results in my game. I just have to be patient.
"I scored a lot of goals in Holland. Many of them were from chances similar to those I had against Blackburn. Usually, they would go in for me. It's just a matter of time before it all comes back."