But Hamilton has admitted that, with the benefit of hindsight, he is now far more relaxed about the situation ahead of this weekend’s Canadian Grand Prix.
“I've got to say that the whole rivalry thing with Nico has been overblown,” Hamilton wrote in his column for BBC Sport.
“Of course, all the best F1 drivers don't like losing. That's a fact. We're all here to win and people know I can't lie and pretend to be happy when I've come up short. I want to win, pure and simple."
Hamilton appeared extremely unhappy following his second-place finish to Rosberg in Monaco, with the Brit’s body language on the podium making his feelings clear. However, Hamilton says there is no bad blood.
“In these moments, in the heat and noise of the battle, you can forget the bigger picture and with me I always feel better after I've slept on it. The next morning I get up and everything is still there outside my window.
“The immediate emotions start to subside, a sense of rationality taps on my shoulder and I realise that it wasn't the end of the world as I thought it had been. I still had Canada and the rest of the season to look forward to!"
Hamilton and Rosberg's rivalry has recently been spoofed in a TV advert for German financial services giant Allianz (below). The pair head into this weekend's race at Circuit Gilles Villeneuve with Rosberg four points clear of his team-mate, though Hamilton has won four races to the German's two in 2014.