I'd say that 70% of the crap that comes off my vise will never see the inside of a fishes mouth. I find myself tying a lot of saltwater and bass flies, even though I will likely never use them. Whatever, it is fun. Occasionally I will create a killer pattern that SHOULDN'T work, but does -- go figure. For example, I took a pink metal bead head, secured it and tied on two strands of chenille, black and purple. I tied on a piece of 20lb mono that hung off the back, attached a stinger hook, and then wrapped/twisted the chenille down the mono and secured it to the stinger hook. It's a completely worthless looking fly, but damn if it doesn't look just like a leech with some roe in its mouth. I used it on my favorite carp spot and drilled two monsters before it finally broke off. I was

. I've retied the same pattern with a few new tricks, including adding a tungsten bead to the middle of the mono in order to induce some kind of movement, as well as put a small snatch of marabou on the end of the stinger hook -- gives it just that much more life.
Long story short, a fly that had no business ever going into my pack has ended up being a go-to stud this year. THAT is what I love about tying/fishing.
Here is a shot of the fly in action:
Here is a small bucketmouth that also took it: