I thought I couldn't run - was the wrong shape, found it horrible etc etc, and that all the people who raved about C25K must have secretly been the cool sporty girls at school, and that it really wasn't for the likes of me
But then I screwed up motivation to become more active, and thought I'd give it a go. And it really does work. I did it without much enjoyment - it was a kind of prescription and a chore to be ticked off. But I could feel myself progressing and stuck with it, got through it, and kept running at least 3x a week.
And found that I came to enjoy it, and started adding distance, more challenges, even took running gear on holiday with me. And slowly realised that I'd come to enjoy it, entered events, added more distance (many Halfs, couple of Marathons).
If you'd told me a few years ago that I'd do that, I'd have laughed in your face. But it really happened. And I've met some wonderful people along the way.
One thing I remember from a Runners World article on what advice seasoned runners would give to those starting out - every single person said "go to parkrun, and go early on, even if you can't run that far". You don't have to run it all, it's a run not a race, but going to an event, and seeing yourself make progress can be really motivating. The first time you run every step is a real high point!