Unlucky TSK but a good DNF often serves as extra motivation for not DNFing again, or at least not giving up quite so soon.
From memory I've DNFed:-
My third ever 200 at only 80km. I was woefully unfit but I still reckon I could have got round if I'd applied the HTFU.
A 600 in horrendous weather (plenty of other people packed on that ride). There were 60mph gusts through the Dales. I gave up at 230km or so.
A DIY 200 halfway. I did the first 100 (a calendar ride) with an enormous hangover thinking that it would sort me out but I just felt worse by the end and got the train home instead of riding the 100km home.
Unlucky TSK but a good DNF often serves as extra motivation for not DNFing again, or at least not giving up quite so soon.
From memory I've DNFed:-