So I fired up YouTube and blasted through old favorites, and then (finally) decided to find out more about the lead singer, Rivers Cuomo. I found some interviews, old and recent, where he appears stiff and awkward, not the stereotypically charismatic band lead. Eventually I found these dance lessons on his YouTube channel:
This is bad dancing, and only video 1 of 4. At times the dance instructor can't help but laugh. After getting over my own bemusement, I wondered why Rivers had posted them... Then realized, intentional or not, they are a gift.
First, I reminded myself I also suck at dancing. Most of the things I reflexively laugh at other people for being bad at, I am also bad at. I have higher expectations for them for whatever reason. ("A rock star should be good at dancing"—but why?) Second, I didn't lose respect for Rivers; I admired his confidence not to care. Which leads to the third point: that the gift of these videos is permission (or rather, a reminder to give ourselves permission) to be bad at something and feel okay about it. These dance lessons are a living acknowledgement of how we all suck at things when we start, and an example of someone continuing in spite of that. A person likely only takes multiple lessons if they think they're going to get better. 
Another message I got from reading about Rivers is that as a kid he knew what he wanted to do: play in a rock band. The man can play the guitar, and from interviews, it seems he's confident he can write catchy songs. In one interview someone asks how he writes songs; he says, pretty casually, he's gotten a room at home "mirror'd out," and he dances and sings in front of the mirrors and "usually some good stuff comes out."
On the other hand, his singing is fine, but not great. (My opinion.) Not my opinion: for the early part of his career he had bad performance anxiety and poor stage presence. He described himself as a "shoe-gazer" on stage for the first 15 years and admitted it was probably not much fun for fans at concerts. These handicaps would dissuade most of us from starting a rock band, and he was fully aware of them and set out to found Weezer anyway. Lucky for us.
The fear of being judged—even by myself—stops me from doing things, and I have to remind myself that okay will get you pretty far, and to embrace the suck.
 My history with Weezer began relatively recently, compared to growing up with classical music and John Denver. One of my first roommates in college loved the band. It took me a while to get past my initial dislike of their rough, grungy sound and a style I found over-the-top and dopey. A night of Rock Band at the college newspaper during which one of our lead reporters (and eventual writer for WashPo) sang a fetching rendition of El Scorcho helped. Pink Triangle and Across the Sea were other "gateway" songs, where I got sucked in by the sad, absurd yet charming lyrics, then realized the music is really perfect for what they were saying. Weezer got me through tough times those four years.
 It would be funny, if after all this analysis, the real reason behind posting these videos is Rivers lost a bet. But it wouldn't matter. The good has already been done.