Ich kann es nicht besser sagen als Ben Racz in den YouTube Kommentaren:

I can’t get over the powerful melancholy in this song. It’s like a yearning for your youth, while appreciating how much more yourself you are with age. It’s telling your younger self things will get better, while realising that they kind of didn’t. It’s reflecting on how much has changed with the passing of time, but the slap in the face that nothing has really changed at all… I think we get so caught up in nostalgia and regret and concern for the future that we forget that our memories aren’t really truthful, and everything we experience is relative and fixed in the time it is in. This song reminds me to focus less on where you’ve been and where you’re going, and more on where you are now 🙁 🙂

https://www.youtube.com/watch?v=j7sTHoeH0eA&t=267s