Hook has a sound somewhere between the "One Headlight" era of The Wallflowers and Tom Petty. Listening to "Best Days" make me think that the song is about their best days- that they are, in fact, living their best life. After the pandemic shut most everything down, I feel like we were all trapped inside and now we want to come back outside and live our lives to their fullest. This is actually not what this song is directly about, but it is also kind of about it if you think about it in reverse.
The first verse of this song is about going to a party where no one was there that you liked so you go back home. The chorus has the lines: "These are the best days of my life / I can't imagine anything worse that" To me, that makes me think about something like college and your youth- how they're supposed to be your best days but sometimes don't end up being that great. So this song isn't really about the "Best Days" but rather days which were thought to be good but turned out to be bad.
Through images of the artists playing and singing from just driving around in the streets this music video is in black and white/greyscale but has this red/blue tint to it which makes it feel like you could watch it with 3-D glasses on. It's kind of funny that the video seems to be about not doing a lot- driving around and hanging out inside- but I feel like I spent a lot of my youth that way and it was rather fun. I wasn't going out getting into too much trouble, but to have that carefree mentality again where even if you have to wake up for work the next day you didn't care and just did it anyway.
With the power of this rock song you can hopefully determine which days you thought might be great but turned out to be lackluster. If we don't have bad days though we don't fully know how to appreciate the good days. So, even though this song might not be directly about having the "Best Days", the idea that you can also use this song to help you pinpoint the days which you thought would be good and were good just makes it feel like in some underlying manner it could really be about the "Best Days". If that confuses you just enjoy the song for what it is and that's a rock hit.