This is the year of DNFs for me. I've now DNF'd a 200 for the first time due to my own mistakes with a bottom bracket bearing install... dunno what went wrong exactly but it seems like I didn't press the bearings in far enough... thought they felt like they were touching the lip/ridge but it appeared they migrated further inward so the crank was moving side-to-side. I thought it was the fixing bolt that came undone but when I got home I had to use a cheater to get it undone, so it was likely still tight.
I also gave up on a 600k, had done the first day in good time (for me), finishing ~360km by 10pm and was asleep by 11, so I should have been fine to finish the next day but my knee was screaming on the first few small hills and I could barely push a 100w without aggravating it so I figured it was best to quit close to the start/finish. I dunno if it would have got better or not, but that's the second DNF for me on this route, last year I crashed and a gash on my elbow wouldn't stop bleeding after another ~200km so I quit to go get it stitched shut.
I guess the thing I learned it that I've been riding on borrowed time when it comes to bike maintenance, and that I haven't been riding or training enough to just roll out the door and knock out a bunch of brevets... kinda gave up on training after I got covid and have been in a funk ever since. Gonna see if I can get a prescription for some low-dose antidepressants to even the keel and get back on track with things.
On the bright side, I converted my road bike to tubeless... I guess one of my problems was non-tubeless rim tape on tubeless-ready rims... but I'm done with tubes on the road bike, the gp5000 seem like really fast tires and no wincing anytime I hit a pothole or what looks like glass was pretty nice on the first half of that 600.