Avril Lavigne just celebrated her most unbelievable and emotional anniversary yet! The star revealed it had been officially a whopping twenty years since the release of her very first album, Let Go.MORE: Avril Lavigne makes rare comments about her childhoodThe singer shared the unforgettable cover of the 2002 album, featuring Avril in her best early aughts grungy self along with a lengthy, heartfelt tribute to the album and everyone who made it possible.She was in as much disbelief herself as fans were with the revelation, writing: "I will never be able to fully explain not only how much this album meant to me, but the monumental impact it has had on my life."WATCH: Avril's fiancé Mod Sun supports her from backstageMORE: Avril Lavigne goes bold in black leather gown for Juno Awards red carpet"It's hard to try and comprehend how, 20 years later, the songs I wrote as a 17 year old would still resonate with people today. It's pretty crazy," she thoughtfully expressed.The punk rock star detailed the wild adventure that followed the album's debut, saying: "It put me on a path and took me places I never in my wildest dreams could have ever expected and I am thankful for it every single day."She gave a sweet shoutout to those who guided her throughout the early stages of her career and beyond, writing: "I will always be grateful to you guys for letting me be myself.