The I chord goes the the IV chord and then to the V. It resolves back to the I.
You use these elements to build structures for verses, bridges, and choruses. What in the world went wrong here?
This song seems to have three distinct sections. The band first come barrelling in with a I-IV progression and the continuation of this is how the verse begins, riding that fifth scale degree in the melody and ready to plunge gloriously into some inevitable cadence. By the end of the second line, things are already going wrong.
The second line instead just flops down onto the tonic note. It doesn't rhyme.
Neither do the third and fourth lines. Then, there's a fifth line, "I wonder what will come," first scale degree up to the second as the chord changes from I to IV. The second scale degree is not a part of the IV chord.
So, after an irregular set of five lines with no rhyming they pick their odd spot to move up to the V chord. Nevertheless, they ride it out like that cadence is coming
It isn't, though. It's back to the IV chord to start the chorus. This time, it's IV-V, so I guess it's a cadence when it goes from there to I, but they're landing on the downbeat of a consequent line, not an antecedent line. It's not the right time for it. Plus, that first line is only one bar long, not two. Oh boy.
Second line of the chorus starts on that I chord and moves to IV, two bars like the I-IV in the verse. Back in the third line to I-IV again; are we going to have a rhyme here? Nah, instead they extend it two bars by going to the V chord, like that fifth line of the verse. Didn't expect that, did you?
Then, it repeats the IV-V but with a different melody and for the full two bars. Back again, it's repeating that first line, but they treat it differently this time. They treat the two beats on the IV chord as a measure of 2/4 and then hold that V chord for two bars of 4/4. You can't make this stuff up. (Well, of course, the genius that wrote this song did.)
I guess you would call the third section a bridge, but it sounds more like they forgot how the verse went so they're just making up a new one as they go. Along the way, they bulldoze their way into some of the same issues. This time, it's a four-bar phrase for each line with a I-IV-V progression. The second line rhymes with the first (but only after the melody is extended)! Check out the third line, though. This is the clearest cadence they've had yet (IV-V-I), but it's totally in the wrong place! They're landing again on the downbeat of a consequent line.
To resolve this issue, they then repeat the cadence, but they cut off a bar first (the preceding line is only three bars long). It seems to me that this has the effect of creating less impact for the consequent line squaring the section off. Lost in this ongoing netherworld, they then add yet another repetition - a third line. This time, all the lines rhyme.
In case my description here doesn't make it obvious, I believe all of this is joyfully chaotic and fantastic.