The Dutchman is the Reds' third top scorer this season with seven goals, but has still come in for some stick.
He missed crucial opportunities in the stalemate at Blackburn in November, and saw his late close-range header saved by Joe Hart in Sunday's draw at Manchester City.
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."