That is a good question. I have a lot of old ideas that have never been written (or never gotten far enough to be posted, I should say - some of them I've started), but I have a hard time letting go or giving up on them. I'm always like, "Well, maybe someday..." Guilty Roads was one of those ideas I'd been sitting on for at least 5 years before I actually started writing it.
One of my more recent ideas that will probably never be written was a Brian suspense story, tentatively entitled "Hush." I got this idea a couple of years ago when we were still speculating about what was going on with his voice, and the premise was that after having vocal cord surgery, Brian goes to a remote cabin or beach cottage or something by himself to recover, since it would be hard to be around other people when he is on complete vocal rest and can't talk, and he gets kidnapped or held hostage by a crazy fan posing as a home healthcare worker, kind of like a "Misery" situation. (I'll admit, I have always wanted to write another story like that.) He can't scream for help without risking permanent damage to his vocal cords, and since his family and friends know he's not supposed to be talking, they don't expect phone calls from him, so the kidnapper can keep them from suspecting anything for awhile by texting them from his phone. I kinda gave up on the idea once Brian opened up about his real condition, which is not treated with surgery. But I did make a cool banner for it:
http://dreamers-sanctuary.com/hushbanner.pngA really old idea I started writing a couple of different times but never got off the ground was one that dealt with the idea of reincarnation. It was originally going to be an AJ canon story called "Once Upon a Dream," and then it evolved into a Brian AU called "Dreams of Blue Eyes," which I then changed to "The Distance Between Lives," but the basic premise was always that the guy has been having recurring dreams about this girl he's never seen, and then he meets her in real life, and it turns out they were lovers in a past life, soulmates, except they never got a chance to grow old together because one of them was murdered. The story would alternate between the present and the past (which was going to be Civil War era) as they try to solve the mystery of what happened in their former lives and prevent something like it from happening in the present. I have quite an elaborate outline for it and even a couple of chapters written, but I could never get much farther than that. Turns out I don't really like writing historical fiction, and I don't do well with super complex storylines LOL.