In this alt-rock tune, Morissette is frustrated for allowing an ex to get under her skin for so long after their breakup and looks forward to when she'll be able to hear his name without flinching. "I wrote 'Flinch' right after an experience I had in Canada where I almost ran into the person that I'm singing about and drove away," she recalled in the album's track-by-track commentary. "I was surprised at how many years had past but still I was responding to the situation as though I had been spending time with him two minutes earlier. I was kind of ashamed and a little embarrassed, but it was where I was at: just really being curious about how someone can have that much of an effect on me and attributing some of it to the fact that I was very, very young when I was in contact with him. I do believe that I will be able to get to a point where hearing his name or even running into him or hearing from him won't trigger me as much as it did and still does. I don't know when that day will come but I'm singing about it hopefully coming."
This was used on the TV drama Crossing Jordan in the 2002 episode "The Gift of Life."