Have you accidentally deleted a blog post? I just did this the other day as I was working in a hurry to clean up some old posts on one of my blogs, accidentally deleting a post that I wanted to keep.
A few years ago I learned about the Wayback Machine. All you do to find your old post is click this link and put the url of the blog post you are missing, if you can recall the full url, in the field toward the top of the page and click the "take me back" button. You will then see a calendar with certain dates highlighted in blue. Pick the highlighted date that is most current out of these highlighted dates, and you will see an image of your post as it was on that date.
You can "copy" and "paste" your information and re-publish the post as a new post if it is valuable to you. Make sure you check any linked text in your post if you copy and paste as the Wayback site changes the url to include their site.
If you can't recall the url of the particular post, the archive links in the margins are click-able, and you may be able to find it this way. Of course, it is best to back up your blog regularly, something I am trying to do more consistently, but the Wayback Machine has saved me more times than I like to admit.