I didn't think during early weeks that I'd be doing 30+ minutes without having to stop! I did my first Parkrun in Poole today and I think I enjoyed it; for me a bit later and so a bit warmer than normal. Now all I have to do is build my endurance, so that I can run for even longer periods. By the way what a great venue!
I have 15 weeks to my first, and probably last big run. I've got to sort out which programme/schedule to follow to get there. But I've achieved my first goal, so why not my next one.
Good luck to everyone else who might have some doubts - just go for it! It's very satisfying and you can feel superior, which is a good feeling!