I've not written that many stories (19 for those keeping count) but I've recently had to carry out the unpleasant task of pensioning off a couple of the older ones. I've had to do it because I've run out of places that I want to submit them - though that's not to say there aren't more places where they could go.
The decision comes about for a couple of reasons. I typically have about 8-10 stories circulating at any one time. I could have more out there in the ether but the administrative and mental overhead of keeping those flying is about the limit of what I can cope with. I also have a lot of respect for the stories and submitting them willy nilly anywhere and everywhere would not feel right. It has to be said that not all markets are created equal - I'm aiming for a particular section of the genre media and going beyond that would dilute that focus. (Can you dilute a focus? Hmm, perhaps not.)
Anyhoo some of the stories that I've pensioned off are pretty old and were first written three years ago. I'd like to think that I've got better since then so they are not the best advocates for what I can do.
But I look back at affection with those stories even if they are slightly tarnished in memory because they have racked up so many rejections. Mothballing them does not end their usefulness though. They are peppered with useful phrases and ideas that can find a home in another story - one key idea from the retirees became catalyst for a flash story that has been accepted.
There are some that I'm planning to re-write too as I really like the setting and framing idea that got me to dream them up in the first place.
Plus I learned something while writing them and they kept my name in front of editors that I am trying to impress and convince to publish my stuff. Given that, so far, I'm keeping to my stated ambition to write a story a month losing one or two is not so bad. Though I'm going to face a real crisis if any of my work gets published as that will punch a hole in the numbers available to send out.