Probably quite a lot.
Booksie.com is a site for amateur writers where they can share all manner of stories -- true tales of fiction -- as well as their poetry, and get feedback from each other.
Disqus has an Anecdotes and Absurdities group where they share real-life stories.
Sites like this one also generate a lot of anecdotes from the experience of the people answering questions.
There will be many others. A simple Google search will find them for you.
Like Didgeri Doo said, a quick search on the interwebs won't do any harm! My main suggestion is Wattpad. It's a lovely site I use everyday for sharing and reading stories.
Wattpad, Fanfiction.net, Quotev, Archive of our own, some people use blog spot :) I have an account on all of this sites... Archive of our own and Wattoad are wonderful! Fanfiction confuses me a tad bit. Quotev is easy to use.
Experienceproject.com is a good place for that.
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