“Let Me Mend the Past” is a short, emotional song led by Ambrose about a feeling of distance and an urge to set things right. Liner notes indicate that it was a joint effort between Ambrose and Stu with this being the only song on Float Along — Fill Your Lungs to have an Ambrose songwriting credit. Since its release the song has become a fan favorite, transforming from a rarely played early track to a powerful moment of any show it graces.
Before a performance of the song on 2022-11-02, Ambrose told the audience that the song was written about some personal family problems he experienced. “This song's about my mom and her sisters. They all hate each other and I had to live at my grandma's for a bit — or my nan's, sorry. And one of my aunties put up cameras in the hallway and then my cousin came over and went crazy. I was like ‘everyone just chill, just chill.’ Sometimes you just, you know, can't stop and shit. So, just gonna write a song about it instead.” Later on 2024-08-20, Ambrose mentioned that he wrote “Let Me Mend The Past” when he was about twenty years old.
“Let Me Mend the Past” was released on Float Along — Fill Your Lungs on September 27th, 2013.
The first reported performance was on 2013-08-21 at the Bar Open in Naarm (Melbourne) and would be played a handful of times in August of that year during full performances of Float Along — Fill Your Lungs. It would see a few more performances in October and November, before disappearing off of sets based on available data. One of these performances from 2013-11-13 shows that it may have sounded quite different at the time, including a gospel-like intro with an extended outro featuring the first known instance of Ambrose rapping on a Gizzard track. The song returned on 2018-11-24, and became a common song in 2019. A performance of the song from 2019-10-18 even made it into the film Chunky Shrapnel. “Let Me Mend The Past” was played twice in 2020 before the COVID-19 lockdown, and re-emerged as part of the band’s all acoustic shows starting on 2021-12-13. The song returned to the band’s typical sets in 2022 and 2023. The latter had the song carry some emotional weight as it was played as a tribute to Ambrose’s father Broderick Smith, who had passed on April 30th, 2023. The song appeared during the band’s four song set at Smith’s memorial on 2023-05-16.