You miss 100% of the shots you never take.
- Wayne Gretzky
Oh, come on. You knew I'd have to sneak some hockey in here sometime, right?
This is a great quote, though, to think of when you consider submitting stories/novels/poems/articles for publication. If you don't try, if you self-reject either by not sending your work out at all or skip sending your work to high-end markets because you feel like you're not at "their level", then you're "missing" those shots. Maybe you would get rejected. Heck, at least in the world of pro spec-fic short fiction markets, probably you're going to get rejected. Some of these places get a hundred or more submissions for every one slot available in their publication.
Yes, your chance may be small. But unless you go ahead and submit, you've got no chance of getting that publication credit. And (at least metaphorically, if not mathematically) even a small chance is infinitely greater than no chance.