The ending of How I Met Your Mother has been a bit controversial. At least two people besides the writers knew all along what would happen: Ted's kids. They kept the secret for nine years. (Some MeFites might not be entirely surprised either, based on these previous threads.) The ending is a little melancholy, both for the characters and for the fans who have become attached to them over almost a decade. Don't worry, though, 20th Century Fox is already developingHow I Met Your Dad.