Powderfinger frontman Bernard Fanning wrote the lyrics for "My Happiness" as a reflection on the time the band spent touring to promote their work, and the loneliness that came as a result.

"My Happiness" was highly praised by critics, with even negative reviews of Odyssey Number Five noting it as a highlight, especially for its catchy chorus.

[4] The song describes feelings of love and separation; Fanning called it "a sad story of touring and the absence loneliness that comes with it".

Gospel and soul music that is "unashamedly about love and how good it makes you feel" was common during the Odyssey Number Five recording sessions.

The lighter elements of "My Happiness" in comparison to some of the band's earlier work saw Fanning reveal his passion for several other musicians such as James Taylor—something that "five years ago ... would have been an embarrassing thing to say".

[10] "My Happiness" peaked at number 23 on the Hot Modern Rock Tracks, making it the first Powderfinger song to appear on a Billboard chart.

[11] According to Susan Groves of WHRL, part of the song's success came about because very few people knew of Powderfinger, but were drawn towards "My Happiness" because it was "melodic, [and] pretty"—a change from what she described as "middle of the road rock" popular in the United States.

[10] Meanwhile, Australians were "starting to get sick of My Happiness"—Cameron Adams argued in The Hobart Mercury that this was one of the reasons Powderfinger decided to focus on the offshore market.

[12] Powderfinger performed "My Happiness" live on the Late Show with David Letterman while touring North America with British rock group Coldplay.

[14] In Europe, "My Happiness" received approximately four weeks of airplay on German music video program Viva II, and the band sold out for three nights in a row in London, partly due to the success of the single.

Cameron Adams of the Herald Sun wrote that "My Happiness" did not disappoint in the trend of excellent first singles from Powderfinger, citing "Pick You Up" and "The Day You Come" as examples.

[28] Despite praising it as a "Big Rock Anthem™", Richard Jinman of The Sydney Morning Herald complained that "My Happiness" was not as "hummable" as past singles "Passenger" or "These Days".

[35] Darren Bunting wrote in the Hull Daily Mail that "My Happiness" was the best song on Odyssey Number Five, praising "soaring vocals, heartfelt lyrics and chiming guitar".

[37] The music video for "My Happiness" starts at a railway station (Roma Street in Brisbane) with a mother and her son stepping off a train.