This song is about letting go of the past and allowing criticism to roll off your back - it makes no difference what others think.
This was Sum 41's first single and their first video. And yes, that is the rapper DMX in the clip. The video was filmed in Toronto, where DMX was working on the movie Exit Wounds. He crossed paths with the band and offered to make a guest appearance, which Sum 41 accepted.
It really was so easy for Linda Ronstadt to score a hit with her Buddy Holly cover of "It's So Easy." She would sometimes change the lyric to: "It's so easy to have a hit, all you have to do is recycle it."